Stability device for use with percutaneous delivery systems

ABSTRACT

A method of implanting a prosthetic heart valve includes advancing a distal end portion of a catheter shaft through a patient&#39;s vasculature. The distal end portion of the catheter shaft includes an expansion device. A prosthetic heart valve is mounted on the expansion device with the expansion device and the prosthetic heart valve in a compressed configuration. The method further includes positioning the distal end portion of the catheter shaft and the prosthetic heart valve to an implantation location, and expanding the prosthetic heart valve and the expansion device from the compressed configuration to an expanded configuration. The expansion device includes an inner expandable member and a plurality of outer expandable members. The outer expandable members are distributed such that there are gaps providing perfusion passageways between the expansion device and the prosthetic heart valve when the expansion device is in the expanded configuration.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.15/085,842, filed Mar. 30, 2016, which is a continuation of U.S. patentapplication Ser. No. 13/370,215, filed Feb. 9, 2012, which claims thebenefit of U.S. Provisional Application No. 61/442,044, filed Feb. 11,2011, all of which are incorporated by reference herein.

FIELD

The present disclosure is directed to apparatuses and methods that canbe used in the treatment of heart valve disease, including balloonvalvuloplasty and the delivery of transcatheter heart valves.

BACKGROUND

Heart valve disease is a serious problem that involves the malfunctionof one or more valves of the heart. The malfunction can manifest itselfin a variety of manners. For example, valve stenosis is thecalcification or narrowing of a native heart valve. As a result, thenative heart valve is not able to completely open and blood flow throughthe native valve is impeded or restricted. Another example of heartvalve disease is valve insufficiency. Valve insufficiency is the failureof a native heart valve to close properly to prevent leaking, orbackflow, of blood through the valve.

Various methods have been developed to treat heart valve disease. Someof these methods require a balloon member that is expanded within thenative heart valve. For example, a balloon member can be used in avalvuloplasty procedure where the balloon member is positioned withinthe native heart valve and expanded to increase the opening size (i.e.,flow area) of the native heart valve and thereby improve blood flow.Another procedure that can be performed is a valve replacement, in whicha native heart valve is replaced by a prosthetic heart valve. Theimplantation of a prosthetic heart valve in the heart can also involvethe expansion of a balloon member in the valve annulus. For example, theballoon member can be used to increase the size of the native valveprior to implantation of the prosthetic valve and/or it can be used toexpand and deploy the prosthetic heart valve itself. In some procedures,the prosthetic heart valve can comprise a self-expanding device that iscapable of expanding within the annulus upon being released from aconstrained state.

The effectiveness of such procedures is contingent, at least in part,upon the position of the balloon member and/or prosthetic device withinthe native heart valve during expansion of balloon member and/orprosthetic device. However, delivering and maintaining the position ofthe balloon member and/or prosthetic device within the annulus of anative heart valve during these procedures can be challenging due tovarious environmental conditions in the surrounding area, including, forexample, blood flow, pressure changes, and movement of the heart andrelated vessels of the patient.

SUMMARY

In some embodiments, a delivery system is provided for stabilizing acatheter shaft near a treatment location within a patient's body. Thesystem can include a catheter shaft having a distal end portion and atension member coupled to the catheter shaft at a first area adjacent tothe distal end portion and to the delivery system at second area that isproximal to the distal end portion of the catheter shaft. By adjustingthe tension in the tension member, the catheter shaft can be caused toflex between the first and second areas. In some implementations, thesecond area is a location on the catheter shaft proximal to the firstarea, and the tension member is fixedly coupled at the first area andmoveably coupled at the second area so that tension between the firstand second areas can be adjusted. In other implementations, the systemincludes an outer shaft that generally surrounds at least a portion ofthe catheter shaft, the second area comprising a location at a distalportion of the outer shaft and the amount of tension in the tensionmember can be adjusted by moving the first and second areas relative toone another.

In other embodiments, a delivery system includes a catheter shaft havinga distal end portion and at least one expansion member positionedproximal to the distal end portion. The at least one expansion member ismoveable between a collapsed state and an expanded state and in itsexpanded state, the at least one expansion member is configured tostabilize the catheter shaft by contacting a wall of the aortic arch andsubstantially fixing the position of a portion of the catheter shaftrelative to the aortic arch. In some implementations, the expansionmember is a single balloon member that is expandable along an outersurface of the catheter shaft. In other implementations, the at leastone expansion member includes three balloon members that are expandablealong an outer surface of the catheter shaft, and, when in theirexpanded state, the three balloon members generally surround thecatheter shaft.

In another embodiment, a system includes a catheter shaft having adistal end portion that has an increased stiffness relative to rest ofthe catheter shaft. At least one pull wire extends from the distal endportion of the catheter shaft to a proximal portion, with the pull wirebeing configured to cause the distal end portion to flex so that a firstportion contacts the inner wall of the aortic arch and a second portioncontacts the outer wall of the aortic arch to wedge the catheter shaftwithin the aortic arch. In some implementations, the distal end portioncomprises a plurality of locking sections, with the locking sectionsbeing moveable between an unlocked state in which the locking sectionsare moveable relative to one another and a locked state in which thelocking sections are fixed relative to one another, the locked statebeing achieved by pulling on the pull wire. In other implementations,the locking sections comprise interlocking tubes that have respectivechamfered proximal portions that are sized to be received into a distalopening of an adjacent interlocking tube.

In some implementations, the system includes one or more stabilitymembers, and the catheter shaft comprises one or more lumens thatextends along the length the catheter shaft to receive the one or morestability members. The one or more stability members can include aplurality of wires. In other implementations, the one or more stabilitymembers comprise a generally flat strip.

In some implementations, the distal end portion can have increasedstiffness relative to rest of the catheter shaft by having a slottedtube embedded in the catheter shaft. In other implementations, thecatheter shaft can include a coiled member embedded in the cathetershaft.

In another embodiment, a system includes a catheter shaft having adistal end portion sized to extend from the descending aorta, throughthe aortic arch, and into the ascending aorta of the patient. Thecatheter shaft can include at least a first articulating area and asecond articulating area. At least one pull wire can extend from thedistal end portion of the catheter shaft to a proximal portion, with thepull wire being configured to cause the first articulating portion tobend toward an outer wall of the aortic arch and the second articulatingportion to bend toward an inner wall of the aortic arch. The opposingbending directions of the first and second articulating portions cause afirst portion of the catheter shaft to contact the inner wall of theaortic arch and a second portion of the catheter shaft to contact theouter wall of the aortic arch to wedge the catheter shaft within theaortic arch.

In another embodiment, a system includes a catheter shaft having adistal end portion sized to extend from the descending aorta, throughthe aortic arch, and into the ascending aorta of the patient. Thecatheter shaft has at least a first bend area and a second bend areathat allow for a higher amount of bending than at other areas of thecatheter shaft with the first and second bend areas being spaced apartfrom one another. At least one pull wire extends from the distal endportion of the elongate shaft to a proximal portion, with the pull wirebeing configured to cause the catheter shaft to bend at the first andsecond bend points to cause the catheter shaft to wedge within theaortic arch.

In other embodiments, the systems described herein can further includean expansion device configured to extend from the distal end portion ofthe catheter shaft, with the expansion device comprising a balloonmember for expanding a prosthetic device or performing a valvuloplastyprocedure. In some implementations, the expansion device includes aninner expandable member and a plurality of outer expandable members. Theplurality of outer expandable members at least partially surround theinner expandable member and when the expandable member is in theexpanded configuration, gaps between adjacent outer expandable membersprovide perfusion passageways across the expansion device. In otherembodiments, the systems described herein can further include aself-expanding prosthetic device configured to extend from the distalend portion of the catheter shaft.

In another embodiment, a method of stabilizing a catheter shaft near atreatment location within a patient's body is provided. The methodincludes delivering a distal end portion of a catheter shaft through thedescending aorta and across the aortic arch of the patient, with thecatheter shaft having a tension member coupled to the elongate shaft ata first area at or adjacent to the distal end portion of the cathetershaft and at a second area proximal to the distal end portion of thecatheter shaft. Tension is adjusted in the tension member to cause thetension member to move into contact with an inner wall of the aorticarch and to cause a portion of the catheter shaft to flex and move intocontact with an opposing outer wall of the aortic arch, thereby wedgingthe catheter shaft and tension member within the aortic arch. In someimplementations, a pull wire is pulled to increase tension in thetension member, with the pull wire extending from the distal end portionto a proximal end of the catheter shaft.

In another embodiment, a method is provided that includes delivering adistal end portion of a catheter shaft through the descending aorta andacross the aortic arch of the patient, with the catheter shaft having atension member coupled to the catheter shaft at a first area at oradjacent to the distal end portion of the catheter shaft and at a secondarea at a distal end portion of an outer shaft that at least partiallysurrounds the catheter shaft. The catheter shaft is moved relative tothe outer shaft to adjust the tension of the tension member, causing thetension member to move into contact with an inner wall of the aorticarch and causing a portion of the catheter shaft to flex and move intocontact with an opposing outer wall of the aortic arch, thereby wedgingthe catheter shaft and tension member within the aortic arch.

In another embodiment, a method is provided that includes delivering adistal end portion of a catheter shaft through the descending aorta andacross the aortic arch of the patient. At least one expansion member isexpanded, causing the at least one expansion member to extend from anouter surface of the catheter shaft at a location proximal to the distalend portion, with the at least one expansion member expanding to contactat least an inner wall of the aortic arch to substantially fix theposition of a portion of the catheter relative to the aortic arch. Insome implementations, the at least one expansion member comprises asingle balloon member that is expandable along an outer surface of thecatheter shaft. The at least one expansion member can include threeballoon members that are expandable along an outer surface of thecatheter shaft, and, when in their expanded state, the three balloonmembers generally surround the catheter shaft.

In another embodiment, a method can include delivering a distal endportion of a catheter shaft through the descending aorta and across theaortic arch of the patient, with the distal end portion having increasedstiffness relative to rest of the elongate shaft. At least one pull wirethat extends from the distal end portion of the elongate shaft to aproximal portion can be pulled to flex the distal end portion so that afirst portion of the catheter shaft contacts the inner wall of theaortic arch and a second portion of the catheter shaft contacts theouter wall of the aortic arch to wedge the catheter shaft within theaortic arch. In some implementations, the distal end portion includes aplurality of locking sections and the act of pulling on the at least onepull wire causes the locking sections to transition from an unlockedstate in which the locking sections are moveable relative to one anotherand a locked state in which the locking sections are fixed relative toone another. In some implementations, the locking sections compriseinterlocking tubes that have respective chamfered proximal portions thatare sized to be received into a distal opening of an adjacentinterlocking tube.

In another embodiment, a method is provided that includes delivering adistal end portion of a catheter shaft through the descending aorta andacross the aortic arch of the patient, with the catheter shaft having atleast a first articulating area and a second articulating area and withthe first articulating area being proximal to the second articulatingarea. At least one pull wire that extends from the distal end portion ofthe catheter shaft to a proximal portion is pulled to cause the firstarticulating portion to bend toward an outer wall of the aortic arch andthe second articulating portion to bend toward an inner wall of theaortic arch. The opposing bending directions of the first and secondarticulating portions causes a first proximal portion of the cathetershaft to contact the inner wall of the aortic arch and a second distalportion of the catheter shaft to contact the outer wall of the aorticarch to wedge the catheter shaft within the aortic arch.

In another embodiment, a method is provided that includes delivering adistal end portion of a catheter shaft through the descending aorta andacross the aortic arch of the patient, with the catheter shaft having atleast a first bend area and a second bend area that allow for a higheramount of bending than at other areas of the catheter shaft and with thefirst and second bend areas being spaced apart from one another. Atleast one pull wire that extends from the distal end portion of thecatheter shaft to a proximal portion is pulled to cause the elongateshaft to bend at the first and second bend points to cause the elongateshaft to wedge within the aortic arch. The positioning of the bendpoints causes a first proximal portion of the catheter shaft to contactthe outer wall of the aortic arch and a second distal portion of thecatheter shaft to contact the inner wall of the aortic arch to wedge thecatheter shaft within the aortic arch. In some implementations, anexpansion device that extends from the distal end portion of thecatheter shaft is expanded. The expansion device can comprise a balloonmember for expanding a prosthetic device or performing a valvuloplastyprocedure. In some implementations, the expansion device can include aninner expandable member and a plurality of outer expandable members,with the plurality of outer expandable members at least partiallysurrounding the inner expandable member and the expanding of theexpansion device providing gaps between adjacent outer expandablemembers to provide perfusion passageways across the expansion device. Inother implementations, the methods described herein can includereleasing a self-expanding prosthetic device from a sheath that extendsfrom the distal end portion of the catheter shaft.

In other embodiments, the method includes delivering a distal endportion of a catheter shaft through the descending aorta and across theaortic arch of the patient, with the catheter shaft having at least onelumen extending from the distal end portion to a portion of the cathetershaft external to the patient's body. At least one stability member canbe inserted through the at least one lumen to cause the distal endportion of the catheter shaft to move into contact with an outer wall ofthe aortic arch and generally fix or immobilize the catheter shaftrelative to the aortic arch. In some implementations, the at least onelumen includes a plurality of lumens and the at least one stabilitymember includes a plurality of stability members, and the plurality ofstability members are inserted into respect ones of the plurality oflumens. In some implementations, the method includes expanding anexpansion device that extends from the distal end portion of thecatheter shaft, the expansion device comprising a balloon member forexpanding a prosthetic device or performing a valvuloplasty procedure.The expansion device can include an inner expandable member and aplurality of outer expandable members, with the plurality of outerexpandable members at least partially surrounding the inner expandablemember and the expanding of the expansion device providing gaps betweenadjacent outer expandable members to provide perfusion passagewaysacross the expansion device.

In another embodiment, an apparatus for delivering a prosthetic valvethrough the vasculature of a patient is provided. The apparatus includesa main catheter comprising an elongated shaft and a balloon catheterhaving an elongated shaft with at least one opening extending through aside surface of the shaft and a balloon member connected to a distal endportion of the shaft. The shaft of the balloon catheter can be capableof moving longitudinally within the shaft of the main catheter. Theballoon catheter can include a perfusion lumen extending through atleast a portion of the balloon catheter, with the lumen configured topermit blood to pass through the lumen when the balloon member is in anexpanded state, the blood passing through the opening in the shaft ofthe balloon catheter.

In other specific implementations, at least a portion of the ballooncatheter under the balloon member (e.g., in the mounting area of theprosthetic valve) can include a collapsible portion that is moveablebetween a collapsed state which reduces a diameter of the lumen and anexpanded state that increases the diameter of the lumen. In otherspecific implementations, the lumen can include a plurality of separatepassageways extending between a proximal end and a distal end of theballoon member.

In another embodiment, a method for delivering an expandable memberthrough the vasculature of a patient is provided. The method can includethe acts of providing an expandable member at a distal end of anelongate shaft, the expandable member having a distal end and a proximalend, the expandable member comprising an inner expandable member and aplurality of outer expandable members at least partially surrounding theinner expandable member; delivering the expandable member to a treatmentsite; expanding the inner expandable member in a passageway of the bodyof the patient; expanding the plurality of outer expandable members inthe passageway; and permitting blood to pass through a plurality gapsformed between an inner surface of the passageway and the inner andouter expandable members.

In other specific implementations, the method can also include the actsof providing a prosthetic device, positioning the prosthetic device onthe expandable member, and deploying the prosthetic device within thepassageway by the acts of expanding the inner and outer expandablemembers.

In other specific implementations, the act of expanding the innerexpandable member can be performed independently of the act of expandingthe outer expandable members. In other specific implementations, theinner expandable member can include a first inner balloon member thathas a first diameter and a second inner balloon member that has a seconddiameter. The first diameter can be smaller than the second diameter andthe first and second balloon members can be substantially coaxial withone another. The act of expanding the inner expandable member cancomprise first expanding the first inner balloon member and thenexpanding the second inner balloon member. In other specificimplementations, the act of expanding the outer expandable members cancomprise expanding one or more of the outer expandable members beforeexpanding the other of the outer expandable members.

The foregoing and other objects, features, and advantages of theinvention will become more apparent from the following detaileddescription, which proceeds with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a delivery system with an expansion device locatedalong a distal end portion.

FIG. 2A illustrates a partial cross-sectional view of a portion of adelivery system, shown with an expansion device in an expandedconfiguration.

FIG. 2B illustrates a close-up view of the delivery system of FIG. 2A.

FIG. 3 illustrates a view of an expansion device of a delivery system,shown in an expanded configuration.

FIG. 4 illustrates an end view of an expansion device of a deliverysystem, shown in an expanded configuration within an annulus.

FIG. 5A illustrates a view of an expansion device of a delivery system,shown in an expanded configuration.

FIG. 5B illustrates a cross-sectional view taken along line 5B-5B ofFIG. 5A.

FIG. 6 illustrates a cross-sectional view of an alternative expansiondevice of a delivery system.

FIG. 7 illustrates a cross-sectional view of an expansion device, shownin a collapsed state and positioned within an annulus with a prostheticdevice mounted thereon.

FIG. 8 illustrates a cross-sectional view of the expansion device ofFIG. 7, shown in a partially expanded state.

FIG. 9 illustrates a cross-sectional view of the expansion device ofFIG. 7, shown in a fully expanded state.

FIG. 10 illustrates a cross-sectional view of the expansion device ofFIG. 7, shown in an expanded state, with some outer balloon membersdeflated.

FIG. 11 illustrates a cross-sectional view of an expansion device, shownin a collapsed state and positioned within an annulus with a prostheticdevice mounted thereon.

FIG. 12 illustrates a cross-sectional view of the expansion device ofFIG. 11, shown in a partially expanded state.

FIG. 13 illustrates a cross-sectional view of the expansion device ofFIG. 11, shown in a fully expanded state.

FIG. 14 illustrates a partial cross-sectional view of an expansiondevice with a prosthetic device mounted thereon.

FIG. 15 illustrates an expansion device shown in an expanded state withone or more blood perfusion passageways between a distal and proximalend of the expansion device.

FIG. 16 illustrates an expansion device shown in an expanded state withone or more blood perfusion passageways between a distal and proximalend of the expansion device.

FIG. 17 illustrates an expansion device shown in an expanded state withone or more blood perfusion passageways between a distal and proximalend of the expansion device.

FIG. 18A illustrates a side view of an expansion device with an innerballoon member and a plurality of separate outer balloon members, shownin a collapsed configuration.

FIG. 18B illustrates a side view of an expansion device of FIG. 18A,shown in an expanded configuration.

FIG. 19A illustrates a side view of an expansion device with an innerballoon member and an outer balloon member surrounding the inner balloonmember, shown in a collapsed configuration.

FIG. 19B illustrates a side view of an expansion device of FIG. 19A,shown in a partially expanded configuration.

FIG. 19C illustrates a side view of an expansion device of FIG. 19A,shown in an expanded configuration.

FIG. 20 illustrates a partial cross-sectional view of a delivery systemwith one or more perfusion lumens.

FIG. 21 illustrates a partial cross-sectional view of the deliverysystem of FIG. 20, shown with an expansion device in an expandedconfiguration.

FIG. 22 illustrates a partial cross-sectional view of a delivery systemwith one or more perfusion lumens and a collapsible portion.

FIG. 23 illustrates a side view of an expansion device with an innerballoon member and one or more perfusion lumens.

FIG. 24 illustrates a side view of an expansion device with an innerballoon member and one or more perfusion lumens.

FIG. 25A illustrates a partial cross-sectional view of a delivery systemwith one or more perfusion lumens.

FIG. 25B illustrates a cross-sectional view of the delivery system ofFIG. 25A taken along line 25B-25B.

FIG. 26A illustrates a partial cross-sectional view of a delivery systemwith one or more perfusion lumens.

FIG. 26B illustrates a cross-sectional view of the delivery system ofFIG. 26A taken along line 26B-26B.

FIG. 27 illustrates a delivery system and a method and apparatus forsecuring a prosthetic device to a distal end of the delivery system.

FIG. 28 illustrates a delivery system and a method and apparatus forsecuring a prosthetic device to a distal end of the delivery system.

FIG. 29 illustrates a delivery system and a method and apparatus forsecuring a prosthetic device to a distal end of the delivery system.

FIG. 30 illustrates a delivery system and a method and apparatus forsecuring a prosthetic device to a distal end of the delivery system.

FIG. 31 illustrates a delivery system and a method and apparatus forsecuring a prosthetic device to a distal end of the delivery system.

FIG. 32 illustrates an expansion device with a mechanical innerexpansion device and a plurality of outer balloon members, shown in anon-expanded (collapsed) configuration.

FIG. 33 illustrates an expansion device with a mechanical innerexpandable member and a plurality of outer balloon member, shown in apartially expanded configuration.

FIG. 34 illustrates an expansion device with a mechanical innerexpandable member and a plurality of outer balloon member, shown in anexpanded configuration.

FIG. 35 illustrates an embodiment of the expansion device of FIG. 32with the outer balloon members and the majority of the struts removedfor clarity, shown in a non-expanded (collapsed) configuration.

FIG. 36 illustrates an embodiment of the expansion device of FIG. 32with the outer balloon members and the majority of the struts removedfor clarity, shown in an expanded configuration.

FIG. 37 illustrates an embodiment of the expansion device of FIG. 32with majority of the outer balloon members and struts removed forclarity, shown in an expanded configuration.

FIG. 38A illustrates a method of delivering a prosthetic device in acollapsed configuration to a treatment location within a native aorticvalve annulus.

FIG. 38B illustrates a method of deploying the prosthetic device of FIG.38A within the native aortic valve annulus using the expansion device ofFIG. 3.

FIG. 38C illustrates the prosthetic device of FIG. 38A in a deployedstate within the native aortic valve annulus.

FIG. 39 is a schematic view a calcified native aortic valve annulus.

FIG. 40 illustrates a prosthetic heart valve mounted on an expansiondevice.

FIG. 41 illustrates another embodiment of a prosthetic heart valvemounted on an expansion device.

FIG. 42 illustrates an embodiment of an expansion device with aplurality of outer balloon members that have a shorter working length.

FIG. 43A is a cross-sectional view taken along line 43A-43A of FIG. 42.

FIG. 43B is a cross-sectional view taken along line 43B-43B of FIG. 42.

FIG. 44 illustrates a prosthetic heart valve mounted on the expansiondevice shown in

FIG. 42.

FIG. 45 illustrates another embodiment of a prosthetic heart valvemounted on an expansion device.

FIG. 46 illustrates another embodiment of an expansion device withportions of the outer balloon members attached to an outer surface ofthe inner balloon member.

FIG. 47A illustrates another embodiment of an expansion device with tailportions coupled and/or fused together.

FIG. 47B illustrates another embodiment of an expansion device with tailportions fused together.

FIGS. 48A and 48B illustrate another embodiment an expansion device withtail portions fused together.

FIG. 49 illustrates an embodiment of an expansion device formed from asingle balloon member.

FIG. 50A is a cross-sectional view taken along line 50A-50A of FIG. 49.

FIG. 50B is a cross-sectional view taken along line 50B-50B of FIG. 49.

FIG. 51 illustrates a catheter shaft that utilizes a stabilizationmember to provide improved stability within an aortic arch of a patient.

FIG. 52 illustrates another catheter shaft that utilizes a stabilizationmember to provide improved stability within an aortic arch of a patient.

FIG. 53 illustrates a catheter shaft that provides improved stabilitywithin an aortic arch of a patient.

FIG. 54 illustrates another catheter shaft that provides improvedstability within an aortic arch of a patient.

FIGS. 55A and 55B illustrate views of a delivery system that utilizes aplurality of expansion members to provide improved stability within anaortic arch of a patient.

FIGS. 56A and 56B illustrate views of a delivery system that utilizes anexpansion member to provide improved stability within an aortic arch ofa patient.

FIG. 57 illustrates a catheter shaft that provides improved stabilitywithin an aortic arch of a patient.

FIG. 58 illustrates another catheter shaft that provides improvedstability within an aortic arch of a patient.

FIG. 59 illustrates another catheter shaft that provides improvedstability within an aortic arch of a patient.

FIG. 60 illustrates a tube member that can be coupled to a cathetershaft to provide improved stability within an aortic arch of a patient.

FIG. 61 illustrates another catheter shaft that provides improvedstability within an aortic arch of a patient.

FIG. 62 illustrates another catheter shaft that provides improvedstability within an aortic arch of a patient.

FIG. 63 illustrates another catheter shaft that provides improvedstability within an aortic arch of a patient.

FIG. 64 illustrates another catheter shaft that provides improvedstability within an aortic arch of a patient.

FIG. 65 illustrates a catheter shaft having multiple lumens forreceiving stability members to provide improved stability within anaortic arch of a patient.

FIG. 66 illustrates a catheter shaft having a single lumen for receivinga stability member to provide improved stability within an aortic archof a patient.

DETAILED DESCRIPTION

The following description is exemplary in nature and is not intended tolimit the scope, applicability, or configuration of the invention in anyway. Various changes to the described embodiment may be made in thefunction and arrangement of the elements described herein withoutdeparting from the scope of the invention.

As used in this application and in the claims, the singular forms “a,”“an,” and “the” include the plural forms unless the context clearlydictates otherwise. Additionally, the term “includes” means “comprises.”Further, the terms “coupled” and “associated” generally meanelectrically, electromagnetically, and/or physically (e.g., mechanicallyor chemically) coupled or linked and does not exclude the presence ofintermediate elements between the coupled or associated items absentspecific contrary language.

Although the operations of exemplary embodiments of the disclosed methodmay be described in a particular, sequential order for convenientpresentation, it should be understood that disclosed embodiments canencompass an order of operations other than the particular, sequentialorder disclosed. For example, operations described sequentially may insome cases be rearranged or performed concurrently. Further,descriptions and disclosures provided in association with one particularembodiment are not limited to that embodiment, and may be applied to anyembodiment disclosed.

Moreover, for the sake of simplicity, the attached figures may not showthe various ways (readily discernable, based on this disclosure, by oneof ordinary skill in the art) in which the disclosed system, method, andapparatus can be used in combination with other systems, methods, andapparatuses. Additionally, the description sometimes uses terms such as“produce” and “provide” to describe the disclosed method. These termsare high-level abstractions of the actual operations that can beperformed. The actual operations that correspond to these terms can varydepending on the particular implementation and are, based on thisdisclosure, readily discernible by one of ordinary skill in the art.

FIG. 1 shows a delivery apparatus 10 adapted to deliver a prostheticheart valve 12 (e.g., a prosthetic aortic valve) to a heart. Apparatus10 generally includes a steerable guide catheter 14, and a ballooncatheter 16 extending through the guide catheter 14. Balloon catheter 16can comprise multiple lumens to independently deliver fluid to one ormore regions of an expansion device, as described in more detail below.The guide catheter can also be referred to as a flex catheter or a maincatheter. As shown in FIGS. 38A-38C and described in more detail below,prosthetic valve 12 can be configured for deployment within an aorticannulus of a patient.

Guide catheter 14 can include a handle portion 20 and an elongated guidetube, or shaft, 22 extending from handle portion 20. Balloon catheter 16can include a proximal portion 24 adjacent handle portion 20 and anelongated shaft 26 that extends from proximal portion 24 and throughhandle portion 20 and guide tube 22. Handle portion 20 can include aside arm 27 having an internal passage which fluidly communicates withthe one or more lumens defined by the handle portion 20. An expansiondevice 28 (e.g., a plurality of inflatable balloons) can be mounted atthe distal end of balloon catheter 16. In FIG. 1, prosthetic valve 12 ismounted on the expansion device 28 and is shown in a crimped state,providing prosthetic valve 12 with a reduced diameter for delivery tothe heart via the patient's vasculature. It should be understood thatexpansion device 28 can be configured for delivery to a treatmentlocation without a prosthetic heart valve mounted thereon, either foroff-expansion device delivery of the prosthetic valve to a treatmentlocation (as discussed below) or for use of the expansion device in avalvuloplasty procedure.

Although the illustrated embodiments discussed herein refer to theprosthetic heart valve as being crimped or mounted on the expansiondevice for delivery to the treatment location, it should be understoodthat the prosthetic heart valve can be crimped or mounted at a locationdifferent from the location of expansion device (e.g., distal orproximal to expansion device) and repositioned over the expansion deviceat some time before expanding the expansion device and deploying theprosthetic valve. This off-expansion device/off-balloon delivery allowsthe prosthetic valve to be crimped to a lower profile than would bepossible if the prosthetic valve was crimped on top of the expansiondevice. The lower profile permits the physician to more easily navigatethe delivery apparatus (including the crimped prosthetic valve) througha patient's vasculature to the treatment location. The lower profile ofthe crimped prosthetic valve can be particularly helpful when navigatingthrough portions of the patient's vasculature which are particularlynarrow, such as the iliac artery.

A nose piece 32 can be mounted at the distal end of the deliveryapparatus 10 to facilitate advancement of the delivery apparatus 10through the patient's vasculature to the implantation site. In someinstances, it may be useful to have nose piece 32 connected to aseparate elongated shaft so that nose piece 32 can move independently ofother elements of delivery apparatus 10.

Nose piece 32 can be formed of a variety of materials, including variousplastic materials. Alternatively, nose piece 32 can comprise aninflatable balloon member. When inflated, nose piece 32 can generallyform a cone shape, such as is shown in FIG. 1. The inflation of nosepiece 32, when nose piece 32 comprises a balloon member, can be achievedby having a lumen extend from a proximal end of the delivery apparatusto nose piece 32. A fluid pressurizing device can be in fluid contactwith the lumen, and nose piece 32 can be inflated and deflated by thefluid pressurizing device. Nose piece 32 can be inflated to help tracknose piece 32 through the vasculature of a patient and/or to provide asurface against which prosthetic valve 12 can abut, which can helpmaintain the position of prosthetic valve 12 on the delivery apparatusuntil deployment at the treatment site. In other embodiments, discussedin more detail below, nose piece 32 can have one or more lumens toprovide blood perfusion through nose piece 32.

As shown in FIGS. 2A and 2B, in the illustrated configuration ballooncatheter 16 can further include an inner shaft 34 (FIG. 2B) that extendsfrom proximal portion 24 and extends coaxially through outer shaft 26and expansion device 28. Expansion device 28 can be supported on adistal end portion of inner shaft 34 that extends outwardly from outershaft 26 with a proximal end portion 36 of the expansion device securedto the distal end of outer shaft 26 (e.g., with a suitable adhesive).The outer diameter of inner shaft 34 is sized such that an annular spaceis defined between the inner and outer shafts along the entire length ofthe outer shaft. Proximal portion 24 of the balloon catheter can beformed with a fluid passageway 38 that is fluidly connectable to a fluidsource (e.g., a saline source) for inflating the expansion device. Fluidpassageway 38 is in fluid communication with the annular space betweeninner shaft 34 and outer shaft 26 such that fluid from the fluid sourcecan flow through fluid passageway 38, through the space between theshafts, and into expansion device 28 to inflate the same and deployprosthetic valve 12.

Proximal portion 24 also defines an inner lumen 40 that is incommunication with a lumen 42 of inner shaft 34. The lumens 40, 42 inthe illustrated embodiment can be sized to receive the shaft of a nosecatheter, if desired. Inner shaft 34 and outer shaft 26 of the ballooncatheter 16 can be formed from any of various suitable materials, suchas nylon, braided stainless steel wires, or a polyether block amide(commercially available as Pebax®). Shafts 26, 34 can have longitudinalsections formed from different materials in order to vary theflexibility of the shafts along their lengths. Inner shaft 34 can havean inner liner or layer formed of Teflon® to minimize sliding frictionwith a nose catheter shaft.

Expansion device 28 can comprise a plurality of balloon members,including, for example, an inner balloon member 50 and a plurality ofouter balloon members 52, as shown in FIGS. 2A and 2B. As shown moreclearly in FIGS. 3 and 4, the plurality of outer balloon members 52desirably at least partially surround inner balloon member 50. The outerballoon members 52 can be angularly spaced at substantially equalintervals around the outer surface of the inner balloon member 50, asshown.

Each outer balloon member 52 also preferably extends axially along anouter surface 54 of inner balloon member 50. Outer balloon members 52can comprise a main outer surface 53 that is configured to receive andurge against a prosthetic valve (i.e., to radially expand the prostheticheart valve) and/or configured to urge against an inner surface of apassageway (i.e., during a valvuloplasty procedure). In addition, eachouter balloon member 52 can comprise one or more narrowed sections 55located distal and/or proximal to the main outer surface 53.

As best seen in FIG. 3, outer balloon members 52 are preferably fixed ata proximal end 56 and at the distal end 58 of the inner balloon member50. The proximal and distal ends 56, 58 of outer balloon members 52 canbe fixed to the inner balloon member, the outer shaft 26, or otherstructure near the proximal and distal ends 56, 58. If the outer balloonmembers 52 comprise narrowed sections 55, a portion of the narrowedsections 55 that is closest to the proximal and distal ends 56, 58 canbe the portion of the outer balloon member that is fixed to the innerballoon member, the outer shaft or the other related structure.

Outer balloon members 52 can also be fixed to the outer surface 54 ofinner balloon member 50 at positions intermediate to the proximal ordistal ends 56, 58; however, each outer balloon member 52 is desirablyfixed only at the proximal and distal ends 56, 58 so that a portion ofouter balloon members 52 between the proximal and distal ends 56, 58 canfreely move relative to the outer surface 54 of the inner balloon member50. By not fixing the outer balloon members 52 to the outer surface 54of inner balloon member 50, outer balloon members 52 can freely movealong the outer surface 54. This freedom of movement allows the outerballoon members 52 to achieve a lower profile when compressed becausethey are able to self-align and/or move into gaps in the compressedprofile of expansion device 28.

As shown in FIG. 4, when expansion device 28 is inflated (expanded) inan annulus 61 (or other similar orifice or passageway in the body), oneor more gaps 60 are preferably provided between at least two adjacentouter balloon members 52. Preferably, each outer balloon member 52 isspaced apart from an adjacent outer balloon members 52 so that a side(outer) surface 62 of a first outer balloon member 52 does not contact afacing side surface 62 of an adjacent outer balloon member 52. Thus, oneor more gaps 60 can permit blood perfusion through the body passagewaybetween the distal and proximal ends 56, 58 of expansion device 28 whenexpansion device 28 in an expanded configuration.

It should be understood that the number and size of outer balloonmembers 52 can vary. For example, if the final desired expanded innerdiameter of a prosthetic device is about 23 mm, the expanded diameter ofthe expansion device can be configured in a variety of ways to achievethis expansion. For example, inner balloon member 50 can have anexpanded diameter of about 15 mm and seven outer balloon members (FIG.4) can have an expanded diameter of about 4 mm each. Thus, the finalexpanded diameter of the expansion device is about 23 mm—the samediameter as the desired inner diameter of the expanded prostheticdevice. In another example, inner balloon member 50 can have an expandeddiameter that is about 17 mm. If the prosthetic device should beexpanded to about 23 mm (as described in the previous example), theexpanded diameters of outer balloon members 52 should be smaller than inthe previous example. In this case, for example, the expanded diametersof outer balloon members 52 can be about 3 mm to achieve the samediameter of expansion as in the previous example (i.e., 23 mm).

In some embodiments, there are at least five outer balloon members. Byproviding at least five outer balloon members, the outer profile of theexpansion device can approximate a circle in cross section. Morepreferably, there are at least seven outer balloon members as shown inFIG. 4 to provide a rounder cross-sectional profile with the outerprofile of the expansion device. As described in more detail below, itcan be particularly desirable to approximate a circular cross sectionwhen expanding a prosthetic heart valve using the expansion devicesdisclosed herein.

FIG. 5A illustrates another embodiment of an expansion device 28comprising an inner balloon member 50 and a plurality of outer balloonmembers 52. FIG. 5B illustrates a cross-sectional view of the expansiondevice 28, which shows that this embodiment includes eight outer balloonmembers 52. As discussed above, the outer balloon members 52 arepreferably not fixed to the inner balloon member 50 between the proximalend 56 and distal end 58 of the expansion device 28. Each outer balloonmember 52 can be secured at its respective proximal or distal ends tothe proximal and distal ends respectively of the inner balloon member.If desired, outer balloon members 52 can taper to a smaller diameter (asshown in FIG. 5A) or have narrowed sections (as shown in FIG. 3) at theproximal and distal ends 56, 58.

Referring to FIG. 6, a cross-sectional view of another embodiment isprovided. In the embodiment shown in FIG. 6, an expansion device 70comprises a plurality of inner balloon members 72 and a plurality ofouter balloon members 74. A shaft 76 of the balloon catheter can extendthrough the expansion device between inner balloon members 72.

Multiple inner balloon members 72 can be used to create a balloonassembly that is capable of achieving various shapes. For example, threeinner balloon members 72 can be used to create an expanded shape that isgenerally tri-lobular in cross section (as shown in FIG. 6). Atri-lobular shape can be useful, for example, when expanding prostheticvalves into portions of the aortic valve and/or aortic root.Alternatively, the inner balloon members and outer balloon members canbe selected so that the expanded shape of the expansion device issubstantially circular in cross section, as in the embodiments describedabove. Of course, if desired, in the embodiments described above with asingle inner balloon member, the sizes (i.e., expanded diameters) of theouter balloon members can be varied to form a cross section that is ashape other than circular (e.g., tri-lobular, oval).

In each of the embodiments herein, the balloon members of an expansiondevice can be expanded (inflated) simultaneously or they can be inflatedindividually (e.g., sequentially or in one or more stages). Preferably,each inner balloon member is fluidly separate or distinct from eachouter balloon member. Similarly, each outer balloon member can befluidly separate or distinct from the other outer balloon members. Byseparately expanding at least some of the balloon members, thepassageway in which the expansion device expands can be partially orcompletely occluded for a shorter period of time. For example, FIGS.7-13 illustrate various stages of expansion of an expansion device thatcan be configured to expand a prosthetic device, such as a prostheticheart valve, or to perform a valvuloplasty procedure.

As described in more detail below, in a preferred embodiment, the outerballoons can be expanded in alternating and/or sequential groups toincrease blood flow between the distal end of the expansion device tothe proximal end of the expansion device (and vice versa). Thus, forexample, if two sequentially expandable (and deflatable) sets of outerballoon members are provided, a first set of outer balloon members canbe expanded and then, after expansion of the first set, the second setof outer balloon members can be expanded. At the time the second set isexpanded, the first set can be maintained in their expandedconfiguration. By sequentially expanding the outer balloon members inthis manner, the amount of time that both sets of outer balloon membersare inflated can be reduced, which is beneficial because when all outerballoon members are expanded, the perfusion paths between the ends ofthe expansion device are reduced. Similarly, the two sets of outerballoon members can be sequentially deflated to increase the bloodperfusion paths during the procedure and reduce the amount of time inwhich the perfusion paths are reduced. Although this method is describedwith only two sets of outer balloon members, it should be understoodthat more than two sets of sequentially expandable and/or alternatelyexpandable balloon members can be provided.

In addition, as described in more detail herein, the sequential and/oralternate expansion of members is not limited to outer balloon members.In various embodiments, inner and outer members (balloon or mechanical)can be sequentially expanded and/or collapsed. For example, a firstinner balloon can be expanded and then one or more outer balloons can beexpanded. Alternatively, the outer member(s) can be expanded and thenthe inner member can be expanded.

Referring to FIG. 7, an expansion device is shown in a collapsedconfiguration with a prosthetic device 86 crimped thereon. The expansiondevice comprises an inner balloon member 82 and a plurality of outerballoon members 84 in a deflated configuration and carried on an innershaft 81. Seven outer balloon members 84 are shown, but as discussedabove, in some embodiments, the number of outer balloon members can befewer or greater. Prosthetic device 86 is crimped onto the collapsedexpansion device. As discussed above, each outer balloon member 84preferably has a portion (e.g., a central longitudinal or axial portion)that is freely floating or movable relative to the balloon member 82,which allows outer balloon members 84 to be collapsed to a lower profileshape. To deploy (expand) the prosthetic device 86, the expansion deviceand prosthetic device 86 can be moved to the treatment site (e.g., abody passageway or orifice) where the prosthetic device will beexpanded. The treatment site can be, for example, a native valve annulus80, as shown in FIGS. 7-8. As can be seen in FIG. 7, when the expansiondevice is completely collapsed with the prosthetic valve positionedthereon, blood can pass through the annulus in the space between theouter surface of the crimped prosthetic device 86 and the inner surfaceof the annulus 80.

Referring to FIG. 8, a first stage of deployment can comprise partiallyexpanding the expansion device by expanding inner balloon member 82 toits expanded configuration. The expansion of inner balloon member 82causes prosthetic device 86 to partially expand, as shown in FIG. 8.Thus, inner balloon member 82 can be expanded while outer balloonmembers 84 remain in their collapsed configuration. To facilitate theindependent and/or separate expansion of the inner balloon member andouter balloon members, separate lumen can be provided. In someembodiments, the separate lumen can be in a side-by-side configuration;however, it should be understood that other configurations are possible.

Inner balloon member 82 preferably expands to a size sufficient tomaintain a frictional force on prosthetic device 86. If desired,prosthetic device 86 can be repositioned as necessary by moving theexpansion device (e.g., by moving inner shaft 81 in a proximal or distaldirection). The frictional force on prosthetic device 86 can helpmaintain the position of the prosthetic device 86 on the expansiondevice.

As shown in FIG. 8, because the partially expanded expansion device andprosthetic device 86 have an outer diameter that is less that the innerdiameter of the annulus, blood is still able to pass through the annulusin the space between the outer surface of the partially expandedprosthetic device 86 and the inner surface of the annulus 80.

Referring to FIG. 9, the expansion device is shown in a further expandedconfiguration (e.g., a fully expanded configuration) with inner balloonmember 82 in an expanded state and outer balloon members 84 in anexpanded state. The full expansion of the expansion device also expandsprosthetic device 86 to its fully deployed state. As seen in FIG. 9, andas discussed above with respect to FIG. 4, gaps 60 are present betweeninner balloon member 82 and outer balloon members 84, and betweenannulus 80 and inner balloon member 82. These gaps permit blood to passbetween the proximal and distal ends of prosthetic device 86 when theexpansion device is in a fully expanded condition.

Accordingly, as shown in FIGS. 7-9, the expansion device can expand aprosthetic device while permitting blood perfusion between proximal anddistal ends of the expansion device. Moreover, the expansion device canbe expanded in stages to maximize blood flow during deployment of aprosthetic device (or during a valvuloplasty procedure). Also, becauseinner balloon member 82 can be fully expanded when the prosthetic deviceis in a partially expanded configuration, the size and shape of thepartially expanded expansion device is predictable. In contrast,although a conventional balloon member can be partially expanded duringexpansion of a delivery device, the shape of the conventional balloonmember is generally unpredictable during expansion because balloonmembers do not tend to conform to predictable shapes until fullexpansion of the balloon member is achieved.

In some embodiments, outer balloon members 84 can be expanded beforeinner balloon member 82 is expanded. Preferably, when expanding outerballoon members 84 first, outer balloon members 84 can be collectivelyexpanded to a size sufficient to maintain a frictional force onprosthetic device 86 to achieve the same repositionability as describedabove with respect to the embodiment where inner balloon member 82 isexpanded first.

In another embodiment, outer balloon members 84 can be separatelyexpanded relative to one another. Thus, as shown in FIG. 10, innerballoon member 82 can be expanded to partially expand the prostheticdevice 86, and then outer balloon members 84 can be expanded in stages.For example, as shown in FIG. 10, alternating outer balloon members 84are shown in an expanded state. In this manner, gaps 60 that are presentbetween inner balloon member 82 and annulus 80 are larger than thosedescribed above in FIG. 9, and greater blood perfusion is possiblethrough gaps 60.

The configuration shown in FIG. 10 can be illustrative of a deploymentstage of a prosthetic device 86 or it can be illustrative of thecollapsing of the expansion device after deployment of prosthetic device86. That is, the deflated outer balloon members 84 shown in FIG. 10 canbe in an intermediate stage and subsequently inflated to assist in theexpansion of prosthetic device 86. Alternatively, the configurationshown in FIG. 10 can be illustrative of a selective collapsing(deflation) of one or more outer balloon members 84 after the prostheticdevice 86 is fully deployed. Thus, the expansion device can quicklyreduce its profile to allow for increased blood perfusion prior to beingcompletely deflated or collapsed.

After expansion of the expansion device (e.g., to expand a prostheticdevice or perform valvuloplasty), the expansion device can also bedeflated or collapsed in stages. For example, the outer balloons can bedeflated prior to deflation of the inner balloon(s). In this manner,blood can be permitted to pass between the proximal and distal ends ofthe expansion device in the areas adjacent to the deflated balloonmembers and the urgency to deflate the remaining expanded balloonmembers can be lessened.

In another embodiment, an expansion device can comprise a multi-diameterinner balloon assembly comprised of a plurality of coaxially arrangedinner balloon members configured such that the inner balloon members canbe expanded to different diameters. For example, FIG. 11 illustrates anexpansion device 100 with a prosthetic device 102 (e.g., a prostheticvalve) crimped thereon. Expansion device 100 can comprise a first innerballoon member 104 and a second inner balloon member 106. First andsecond inner balloon members 104, 106 are preferably coaxial. In theillustrated embodiment, first and second balloon members 104, 106 canboth be carried on an inner shaft 107. In a manner similar to thatdescribed above, a plurality of outer balloon members 108 can at leastpartially surround the first and second inner balloon members 104, 106.

First inner balloon member 104 and second inner balloon member 106preferably have different diameters so that the expansion device 100 caninflate to a plurality of predictable, increasing diameters. Forexample, first inner balloon member 104 can have a smaller inflateddiameter than second inner balloon member 106. Thus, as shown in FIG.12, when expansion device 100 is inflated (expanded) to a firstconfiguration, in which first inner balloon member 104 is fully inflatedand outer balloon members 108 are fully inflated, the total inflateddiameter (profile) of the expansion device is less than that of an innerdiameter of an annulus 110. However, as shown in FIG. 13, when expansiondevice 100 is inflated (expanded) to a second configuration, in whichsecond inner balloon member 106 is fully inflated and outer balloonmembers 108 are fully inflated, the total inflated diameter (profile) ofthe expansion device is substantially the same as the inner diameter ofthe annulus 110.

Thus, the expansion device can be inflated (expanded) in stagescharacterized by predictable, increasing diameters. That is, theexpansion of the expansion device can include an intermediate stage(FIG. 12) between the deflated stage (FIG. 11) and the fully expandedstage (FIG. 13). As shown in FIG. 12, in this intermediate stage theexpansion device 100 is only partially expanded and blood can moreeasily pass between the proximal and distal ends of expansion device100. Preferably, first and second inner balloon members are concentricand coaxial so that they can expand in a predictable and uniform mannerrelative to the prosthetic device. In addition, as in other embodiments,it should be understood that even in the fully expanded stage (FIG. 13),blood is able to pass between proximal and distal ends of expansiondevice 100 by passing through the gaps (spaces) 109 present betweenadjacent outer balloon members 108.

As noted above, an inner member can be inflated before one or more outermembers, or one or more outer members can be inflated before the innermember. By expanding the outer members first, gaps (e.g., passageways)can be formed between adjacent outer balloon members early in theexpansion procedure. These gaps between adjacent outer balloons can bemaintained as the inner member is expanded. In this manner, the gaps inthe expansion device are present as the expansion device moves from apartially expanded state to a fully expanded state and blood can beallowed to flow across the device throughout the expansion procedure.

In another embodiment, the expansion device can comprise an innerballoon member 127 and a plurality of outer balloon members 128 at leastpartially surrounding inner balloon member 127. Outer balloon members128 can be oriented relative to a prosthetic device 120 to increaseperfusion between distal and proximal ends of prosthetic device 120. Forexample, as shown in FIG. 14, a prosthetic device 120 can comprise aframe member 122 and a plurality of leaflets 124 coupled to frame member122. Adjacent leaflets 124 form a plurality of commissures 126. As shownin FIG. 14, prosthetic device 120 can be mounted on the expansion deviceso that outer balloon members 128 are not aligned with (or spaced awayfrom) the commissures 126. By positioning the outer balloon members 128so that they are not located at the area of commissure 126, maximumblood perfusion between proximal and distal ends of the prostheticdevice 120 can be achieved by taking advantage of blood flow through theprosthetic device 120 itself.

Although the balloon members described above can be formed in variouscross-sectional shapes (e.g., round, tri-lobular, oval, etc.), they arepreferably substantially round in cross section. When subjected to highpressure inflation, as is required to expand a prosthetic device,balloon members have a tendency to “round out,” regardless of theirpre-set shape. For example, although it possible to heat-set a balloonto have an oval cross section, during high pressure inflation that ovalshape will tend to inflate to a substantially round, cross-sectionalshape. Thus, an advantage of the embodiments described above is thateach balloon member (e.g., inner and outer balloon members) can beconfigured to be round in cross section, yet the overall profile of theexpansion device in cross section is more complex and includes gaps forblood perfusion. Therefore, even when subjected to high pressureexpansion, the final shape of the expansion device is substantially thesame as its preset shape since each balloon has a pre-set shape having asubstantially circular cross-sectional profile. In contrast, balloonmembers having a non-circular cross-sectional profile may distort uponhigh pressure expansion and the final shape of the balloon member maynot be as expected.

In another embodiment, other expansion devices are provided that preventand/or minimize distortion of a balloon member when it undergoes highpressure expansion. Referring to FIG. 15, an expansion device 150 with aplurality of projections is disclosed. Expansion device 150 comprises amain body 152 and a plurality of projections 154 that extend radiallyfrom main body 152 and circumferentially around the main body.Projections 154 define grooves 156 alone the expansion device 150 toallow blood to pass from a proximal end 158 to a distal end 160 of theexpansion device. Projections 154 preferably define both longitudinalgrooves 162 and circumferential grooves 164. Longitudinal grooves 162extend in a substantially longitudinal direction between proximal end158 and distal end 160, while circumferential grooves 164 extend in acircumferential direction around expansion device 150. Preferably,longitudinal grooves 162 extend substantially the length of theexpansion device 150 and circumferential grooves 164 extendsubstantially around the circumference of the main body 152; however, aslong as longitudinal grooves 162 and circumferential grooves 164collectively form a one or more passageways between the proximal anddistal ends 158, 160 of expansion device 150 when expansion device 150is in an expanded configuration in an orifice or passageway of the body,expansion device 150 can effectively permit blood to pass between thetwo ends 158, 160.

As noted above, balloon members have a tendency to distort towards arounded cross-sectional configuration when subjected to high pressures.The circumferential grooves 164 function to minimize the deleteriouseffects of the inflation pressure. Specifically, because circumferentialgrooves 164 preferably extend around the circumference of expansiondevice 150, at those locations the expansion device can achieve acircular cross section when inflated to minimize distortion of expansiondevice 150 at other locations along the length of the balloon member. Inother words, by allowing portions of the expansion device 150 at groovesto achieve a circular cross section, the distortive forces at otherlocations along the longitudinal axis of expansion device 150 areprevented or at least minimized.

Thus, expansion device 150 can have a plurality of circularcross-sectional areas extending along the length of expansion device150. In particular, such circular cross-sectional areas can be at thelocations of the one or more circumferential grooves. In addition,because expansion device has projections and grooves formed between theprojections, the expansion device desirably has a plurality of differentcross-sectional shapes/sizes along the length of expansion device 150.For example, the cross section at a circumferential groove can becircular and of a certain size (diameter), while the cross section atother locations can be non-circular and larger in size than the crosssection of the circumferential groove.

FIG. 16 illustrates another embodiment of an expansion device 150. Theexpansion device of FIG. 16 comprises fewer projections 154 than that ofFIG. 15. In addition, the projections 154 of FIG. 16 are rounded ortapered along the circumferential direction. These rounded portions 166can reduce the likelihood of “blow-out” of the non-circular sections. Asin FIG. 15, longitudinal grooves 162 extend in a substantiallylongitudinal direction between proximal end 158 and distal end 160,while circumferential grooves 164 extend in a circumferential directionaround expansion device 150.

Although each of the expansion devices 150 shown in FIGS. 15 and 16 haveprojections that are uniformly distributed in a grid-like manner, itshould be understood that the projections can be non-uniformly spacedalong the main body of expansion device 150.

In another embodiment, an expansion device 170 is provided. As shown inFIG. 17, expansion device 170 comprises an inner balloon member 172 andan outer balloon member (or projection) 174 that extends from a proximalend 176 to a distal end 178 of expansion device 170. Outer balloonmember 174 extends from proximal end 176 to distal end 178 by wrappingaround the main body of inner balloon member 172 one or more times.Preferably, outer balloon member 174 wraps around inner balloon member172 in the substantially helical manner shown in FIG. 17. Thus, wheninner balloon member 172 and outer balloon member 174 are expanded,blood can perfuse between the proximal and distal ends 176, 178 througha passageway 180 formed between adjacent radially projecting portions ofthe outer balloon member 174. If the outer balloon member 174 extendsaround a surface of the inner balloon member 172 in a substantiallyhelical configuration, the resulting passageway will also besubstantially helical in shape.

Outer balloon member 174 is preferably coupled to inner balloon member172 so as to maintain the helical shape when outer balloon member 174 isexpanded. However, it may be preferable to leave portions of outerballoon member free (unattached to inner balloon member 172) so thatexpansion device 170 can have a smaller reduced profile when the balloonmembers are deflated. In other words, as described above with respect tothe embodiment shown in FIG. 3, the outer balloon member 174 canself-align by moving into gaps in the compressed profile of theexpansion device 170.

As discussed above, balloon members preferably have a round crosssection to prevent or reduce the chance of distortion of the balloonmember when inflated. Other shapes, however, may be advantageous. Forexample, FIGS. 18A and 18B illustrate an expansion device 190 similar tothat shown in FIGS. 3 and 4, except that the inner balloon member 192 ispeanut- or dog bone-shaped. That is, inner balloon member 192 has awider radius at portions near the proximal end 194 and distal end 196than at a center portion. A plurality of outer balloon members 198extends substantially the length of the inner balloon member 192. Theouter balloon members can be configured in an identical or substantiallysimilar manner as the outer balloon members of other embodiments. Forexample, as described above with respect to FIGS. 3 and 4, outer balloonmembers 198 can be attached to the inner balloon member 192 at theproximal and distal ends 194, 196 such that a central area of each outerballoon member between the proximal and distal ends 194, 196 is leftunattached to the inner balloon member.

As discussed above and shown, for example, in FIG. 4, outer balloonmembers can be configured to provide gaps for perfusion of blood betweenadjacent balloon members. The use of an inner balloon member that isshaped as shown in FIGS. 18A and 18B can be advantageous when used incombination with a plurality of outer balloon members because it canallow for even more flow between the proximal and distal ends of theexpansion device. In particular, because outer balloon member 198 ispreferably unattached at a central region, an inner surface of outerballoon members 198 can be spaced apart from the inner balloon member192 when expanded, defining additional gaps 199 between the outerballoon member 198 and the inner balloon member 192. These additionalgaps 199 can further facilitate blood flow between the proximal anddistal ends 194, 196.

Moreover, the dog bone-shape of the inner balloon member 192 can help tostabilize the prosthetic valve on the expansion device during theexpansion procedure. That is, the prosthetic valve can be mounted on theprosthetic valve between the proximal and distal ends 194, 196 so thatat least a portion of the two bulbous or radially enlarged regions(i.e., the wide portions of the dog bone-shaped inner balloon member)extend beyond the proximal and distal ends, respectively, of theprosthetic device.

When deploying a prosthetic valve in an annulus (e.g., the aorticannulus), inner balloon member 192 can be expanded to stabilize theprosthetic valve on the expansion device. By mounting the prostheticvalve between the two bulbous regions of the inner balloon member 192,the prosthetic valve can be firmly held on the inner balloon member 192.If desired, the position of the prosthetic valve within the annulus canbe adjusted while the prosthetic valve is firmly mounted on theexpansion device. Once the prosthetic valve is in the proper positionfor deployment, one or more outer balloon members 198 can be expanded asshown in FIG. 18B to fully deploy the prosthetic valve in the annulus.As the outer balloon members 198 expand, outer balloon members 198 pressagainst the inner surface of the prosthetic valve and cause theprosthetic valve to expand to its deployed configuration. Although theouter balloon members 198 are shown in FIG. 18B following the curve ofthe inner balloon member 192, it should be understood that if sufficientpressure is applied to the outer balloon members 198, they will take ona more rod-like (e.g., straight) shape at the area above gaps 199.

FIGS. 19A-19C illustrate another embodiment of an expansion device. Theexpansion device 190 of FIGS. 19A-19C is similar to that shown in FIGS.18A and 18B, except that instead of a plurality of outer balloonmembers, there is a single outer balloon member 198 that surrounds theinner balloon member 192. As in the embodiment, of FIGS. 18A and 18B,the inner balloon member 192 can be expanded to stabilize or secure theprosthetic device on the inner balloon member 192 (FIG. 19B). Then, byexpanding the outer balloon member 198, the prosthetic device can befully deployed within an annulus (FIG. 19C). While the embodiment ofFIGS. 19A-19C includes the dog bone-shaped inner balloon member 192, itdoes not provide for gaps 199 as shown in FIGS. 18A-18B since the outerballoon member 198 fully surrounds inner balloon member 192 in thisembodiment.

In other embodiments, other techniques, devices, and methods can be usedto increase blood perfusion between proximal and distal ends of anexpansion device mounted at the distal end of a delivery device. FIG. 20illustrates a perfusion device, or catheter assembly, 200 that includesan inner tube, or catheter, 202 with a lumen 204 passing therethrough. Aballoon member 206 can extend over a portion of the inner tube 202 and aprosthetic device 208 (e.g., a prosthetic valve) can be crimped onto theballoon member 206. An outer tube, sheath, or catheter, 210 (sheath) canextend along at least a portion of inner tube 202. A nose cone 212 canbe provided at a distal end of inner tube 202. Balloon member 206 cancomprise a conventional inflatable balloon or one of the expansiondevices described herein.

Lumen 204 can be configured to receive a guide wire (not shown). Afterthe prosthetic device is advanced to a deployment position for expansionin the body, the guide wire can be removed from the lumen 204 (or atleast removed from the distal end of the lumen) and blood can be allowedto perfuse between a distal end 216 and a proximal end 214 of balloonmember 206. Referring to FIG. 20, blood can flow in the direction ofarrows 218 through nose cone 212 and lumen 204. To facilitate blood flowout of lumen 204, one or more openings 220 can be provided in inner tube202. Also, if outer tube 210 is positioned over inner tube 202, outertube 210 can also comprise a plurality of openings 222. Preferably, theopenings 222 in outer tube 210 can be aligned or positioned adjacent toopenings 220 in inner tube 202 to facilitate blood flow out of the lumenat the proximal end 214 of balloon member 206.

FIG. 21 illustrates an expanded configuration of the perfusion device200 of FIG. 20. As shown in FIG. 21, balloon member 206 can be expandedto deploy prosthetic device 208. During the expansion of balloon member206, blood flow between the distal and proximal ends of the balloonmember 206 can be restricted by balloon member 206. However, byproviding an internal passageway (lumen 204) through which blood canflow, the restriction of blood flow through the passageway can bereduced. In addition, if perfusion device 200 is used with the inner andouter balloon member configurations disclosed in other embodiments,blood perfusion can be further increased.

In a modification of perfusion device 200, as shown in FIG. 22, innertube 202 can comprise a collapsible member or collapsible portion 226.Thus, as shown in FIG. 22, the collapsible member 226 can receive acrimped prosthetic device 208 and achieve a lower profile by collapsingto a smaller diameter when the prosthetic device 208 is crimped thereon.Since blood perfusion through the lumen 204 is primarily required whenthe balloon member 206 is in an expanded configuration (FIG. 21), thenarrowed lumen 204 of collapsible member 226 when the prosthetic deviceis in a collapsed (crimped) configuration (FIG. 22) does notsignificantly restrict blood flow.

When the compressive force on the collapsible member 226 is removed byexpanding the balloon member 206, the collapsible member 226 desirablyreturns to a larger diameter configuration (such as is shown in FIG.21). Conventional tubing material may not recover sufficiently to allowfor sufficient blood flow through the lumen. In addition, conventionaltubing may kink, break, or otherwise fail when crushed (collapsed) bythe force of the crimped prosthetic valve or when later expanded by theinward force applied by the balloon member 206 during inflation.Accordingly, collapsible member 226 is preferably formed of a resilientmaterial, such as Nitinol. In a preferred embodiment, collapsible member226 comprises a braid formed of Nitinol.

As discussed above, a perfusion lumen can be used in combination withthe multi-balloon expansion devices described herein. For example, FIGS.23 and 24 illustrate expansion devices 250 that include an inner balloonmember 252 and a plurality of outer balloon members 254, and which areused in combination with a perfusion lumen 256 of an inner tube 258.Perfusion lumen 256 extends between proximal and distal ends ofexpansion device 250. Expansion devices 250 of FIGS. 23 and 24 aresubstantially the same, except that inner balloon member 252 of FIG. 24has a shape that is substantially peanut-shaped or dogbone-shaped, asdescribed above with regard to FIGS. 18A and 18B. It should beunderstood that expansion devices 250 can take the form of any expansiondevices discussed herein, and lumen 256 can be configured to allow thepassage of blood between proximal and distal ends of expansion device asdescribed in any of the embodiments herein.

In other embodiments, the perfusion passageway between proximal anddistal ends of the expansion device can comprise one or more lumens. Forexample, as shown in FIGS. 25A and 25B, a perfusion device, or catheterassembly, 300 comprises a tube 302 that has a single lumen 304 for bloodperfusion between a distal end 308 and proximal end 306 of an expansiondevice 310. An opening 312 in the tube 302 permits blood to flow fromthe lumen 304. Perfusion of blood through lumen 304 can be achieved inthe manner identical to or substantially similar to that described abovewith respect to FIGS. 20 and 21.

In another embodiment shown in FIGS. 26A and 26B, a perfusion device, orcatheter assembly, 320 comprises a tube, or catheter, 322 that hasmultiple lumens 324 for blood perfusion between a proximal end 326 anddistal end 328 of an expansion device 330. One or more openings 332 inthe tube 322 permit blood to flow outwardly from the one or more lumens324. Desirably, tube 322 is formed with at least one opening 332 influid communication with each lumen. Again, perfusion of blood throughlumens 324 can be achieved in the manner identical to or substantiallysimilar to that described above with respect to FIGS. 20 and 21.However, because there are multiple lumens 324 for blood perfusion, itmay be more desirable to include multiple openings 332 that can bealigned with the respective openings in an outer shaft (not shown).

The above embodiments disclose methods for deploying expansion devicesin an orifice or passageway of the body. By providing mechanisms forallowing and/or increasing blood perfusion between the expansiondevices, a physician can have additional time to deploy (or collapse)the expansion device and the risk of significant adverse effects due toblood occlusion through the orifice or passageway can be reduced.

Additional embodiments are disclosed for securing a prosthetic device toa distal end portion of a delivery device. FIG. 27 illustrates anapparatus and device for releasably securing the prosthetic device usinga release wire. A delivery apparatus 400 comprises an inner tube, orcatheter, 402 and an outer tube, or catheter, 404 (sheath). A balloonmember 406 and nose cone 408 are positioned at a distal end of innertube 402. A prosthetic device 410 can be secured to the inner tube viaone or more tethers (e.g., wires) 412 that extend into respectiveopenings on the prosthetic device 410. Each tether 412 passes through anopening on the prosthetic device 410, and one or more release wires 414are passed through an opening or loop 416 at the end of a respectivetether 412 to secure the prosthetic device 410 to the inner tube. Therelease wires 414 can be coupled to outer tube 404 and the retraction(proximal movement) of outer tube 404 relative to inner tube 402 cancause release wires 414 to be removed from openings 416 of tethers 412,allowing the loops 416 to be pulled through their respective openings onprosthetic device 410 and thereby releasing prosthetic device 410 fromthe connection formed by tethers 412 and release wires 414.Alternatively, release wires 414 can extend proximally to a handle (notshown) and be moved or released independently of outer tube 404. In theillustrated embodiment, prosthetic device 410 comprises a stentedprosthetic heart valve. The leaflets of the prosthetic valve are omittedfor clarity in the figures.

In another embodiment shown in FIG. 28, delivery apparatus 400 compriseshooking members 420 that extend from a distal end of inner tube 402.Hooking members 420 are preferably biased outwards so that a distal endof each hooking member 420 is held against an opening 421 in prostheticdevice 410. To release the prosthetic device 410, outer tube 404 can bemoved distally relative to inner tube 402 and the hooking members,thereby forcing outwardly-biased hooking members 420 inward as the outertube passes over the hooking members. As the outward tube 404 moves overthe hooking members 420, the hooking members 420 are compressed to theinner diameter of the outer tube, thereby moving the hooking members 420radially inward and out of engagement with openings 421. Thus, theinward force applied to the hooking members 420 by outer tube 404releases prosthetic device 420 from hooking members 420.

In other embodiments, the prosthetic device can be secured to thedelivery apparatus from both ends to provide further maneuverability ofthe prosthetic valve after it has been expanded. FIG. 29 schematically(in partial cross section) illustrates a balloon member 450 that has aplurality of securing members 452 for securing a prosthetic device 454to the balloon member 450. Securing members 452 can comprise holdingflaps that extend distally and proximally, respectively, from theballoon member 450. Holding flaps can be formed integral with theballoon member 450 or they can be separate members that are coupled(glued, stitched, etc.) to the balloon member 450. As balloon member 450deflates, securing members 452 pull away from prosthetic device 454,thereby releasing prosthetic valve 454 from securing members 452.

FIG. 30 illustrates an embodiment in which a prosthetic device (e.g., aprosthetic heart valve) is coupled to a delivery apparatus 500 at bothproximal and distal ends. A hooking member 502 (as discussed above) canbe used to secure a proximal end of a prosthetic device 504, while oneor more sutures 506 can extend from a proximal end of delivery apparatus500 to a distal end of prosthetic device 504. For example, sutures 506can extend through an inner tube 508 from the proximal end of deliveryapparatus 500 and outwardly through openings 505 in a nose cone 510positioned at a distal end of apparatus 500. Sutures 506 can extend fromopenings 505 and loop over and around (or through) a distal portion ofprosthetic device 504. The free end of the sutures can then extend backthrough inner tube 508 to the proximal end of delivery apparatus 500.From the proximal end of delivery apparatus 500, sutures 506 can bereleased to release the distal end of prosthetic device 504.

To maintain tension on the distal end of prosthetic device 504, a springmember 512 can be coupled to each end of the sutures 506 that secureprosthetic device 504. For example, if three sutures 506 are used tosecure the distal end of the prosthetic device 504 (as shown in FIG.27), after the sutures 506 loop through the prosthetic device, six endsof the sutures 506 can be secured to a proximal end of deliveryapparatus 500 (e.g., at spring member 512).

FIG. 31 illustrates an embodiment in which a prosthetic device (e.g., aprosthetic heart valve) is coupled to a delivery apparatus 600 at bothproximal and distal ends of a prosthetic device 604 using sutures. Asshown in FIG. 31, a first set of sutures 602 a can extend through aninner tube 606 from the proximal end of the delivery apparatus and outopenings 609 in a nose cone 610 positioned at a distal end of deliveryapparatus 600. Similarly, a second set of sutures 602 b can extend outof inner tube 608 at an area proximal to the prosthetic valve and securethe proximal end of prosthetic device 604. Sutures 602 a and 602 b canbe coupled to prosthetic device 604 any known manner, including forexample, using the loops discussed above.

The above structures and methods for hooking or otherwise securing aprosthetic device to a portion of the delivery apparatus can beparticularly useful in combination with the multi-stage expansionmechanisms described herein. As a prosthetic device is partiallyexpanded, the forces applied by the balloon member on the prostheticdevice can vary and be less predictable than the forces under fullexpansion, and therefore, the balloon member may not adequately secureor grip the prosthetic valve as it is being expanded to its functionalsize. Thus, when partially expanding a balloon member or providing asystem for expansion of a prosthetic valve in stages, securing mechanismsuch as those described above can be particularly useful because suchsecuring mechanisms can maintain the prosthetic valve at a fixedposition relative to the balloon member to ensure predictable and evenexpansion of the prosthetic valve. Moreover, such securing mechanism canmaintain the prosthetic valve at a fixed position relative to thedelivery apparatus after the prosthetic valve is partially expanded toallow the physician to adjust the position of the prosthetic valve(e.g., proximally or distally) within the body lumen relative to thedeployment site.

Although many of the embodiments disclosed herein have been describedwith reference to expanding a prosthetic device, such as a prostheticheart valve, within an orifice or passageway of the body, it should beunderstood that the expansion devices and perfusion devices disclosedherein can also be used to perform a valvuloplasty procedure. That is,the expansion of the balloon member(s) can be done without a prostheticdevice crimped thereon in a valvuloplasty procedure. The same advantagesof blood perfusion described above with respect to an implantationprocedure will be present in a valvuloplasty procedure, where noprosthetic device is involved.

Additionally, it should be understood that the expansion device need notcomprise all balloon members and, alternatively, can comprise mechanicalexpansion devices. For example, a mechanical expanding member with anopen-frame configuration can comprise the central expanding memberaround which multiple outer balloon members are positioned.

FIGS. 32-37 disclose an illustrated embodiment of an expansion device(expandable basket) 700 with an open-frame configuration. Expansiondevice 700 can comprise a plurality of longitudinally-extending,circumferentially-spaced struts 702 terminating and joined together atopposite ends of the expansion device. As shown in FIG. 32, for example,struts 702 can extend between the distal member (cup) 704 and proximalmember (cup) 706 of the expansion device 700. Struts 702 can be formedof a variety of materials and in a variety of shapes, as long as theshape and structure is sufficiently strong to cause expansion of aprosthetic device, as described in more detail below. For example, eachstrut 702 can be formed of a tubular structure of elastic material, suchas stiff plastic or metal. In addition, the expansion device 700 can beformed of a variety of number of struts 702, so long as the struts areof sufficient number, strength, and/or shape so as to provide sufficientforce to surfaces and/or contact points of the prosthetic device toexpand the device as described herein.

In operation, distal and proximal members 704, 706 can move relative toone another to either expand (by moving closer together) or collapse (bymoving further apart) the expansion device 700. The relative movement ofthe distal and proximal members 704, 706 can be achieved, for example,by translating a central screw mechanism 710 that extends between eachmember and to which each of the member is threadably connected.Referring to FIGS. 35-37, a method of expanding the expansion device 700is shown. For convenience, in each of these figures only a single strut702 is shown. In addition, in FIGS. 35 and 36 the balloon members areremoved for clarity. FIG. 35 illustrates the mechanical portion (i.e.,strut 702) of expansion device 700 in a collapsed configuration. FIG. 36illustrates strut 702 in an expanded configuration, where the two cups(distal and proximal members) 704, 706 have moved closer togetherforcing strut 702 to expand radially. The relative movement of cups 704,706 can be achieved, for example, by rotation of central screw mechanism710. Alternatively, cups 704, 706 can be moved closer together (toradially expand struts 702) or further apart (to radially collapsestruts 702) using other mechanisms, such as by pulling or pushing onwires or rods attached to one or both of cups 704, 706.

FIG. 37 illustrates strut 702 in a fully expanded configuration with anouter balloon member extending along at least a portion of the surfaceof strut 702. The other struts and outer balloon members have beenremoved for clarity. Strut 702 is shown in an expanded configurationwith the outer balloon member 708 also expanded. The sequence ofexpansion can vary. For example, the inner members (struts 702) can beexpanded and then the outer balloon members 708 can be expanded, or,alternatively, the outer balloon members 708 can be expanded before theexpansion of the inner members (struts 702). Also, as shown in FIG. 37,a catheter 711 can extend distally from the proximal end of theexpansion device. Outer balloon members 708 can be expanded by fluiddelivered through a lumen within catheter 711.

A plurality of outer balloon members 708 can be coupled to the struts702. Each outer balloon member 708 is desirably coupled to at least onestrut 702 so that it can maintain its position relative to the struts702. The plurality of struts 702 can each have an outer surface thatdefines a supporting surface for supporting at least one outer balloonmember 708. The width of the supporting surface of each strut can vary.For example, if only one strut 702 supports each outer balloon member708, the strut and the supporting surface can have a greater width.However, if multiple struts 702 support a single outer balloon member708, the width of the strut and support surface can be smaller. Eachstrut 702 in the annular array can be laterally deformable to radiallyexpand or radially contract the annular array of struts 702, and thesupporting surfaces defined by them.

In operation, struts 702 can function similar to the inner balloonmembers disclosed herein. That is, struts 702 have a collapsedconfiguration (FIG. 32) and an expanded configuration (FIG. 33). FIG. 33illustrates the struts 702 in an expanded configuration with outerballoon members remaining in a collapsed configuration. When expansiondevice 700 is expanded, the supporting surfaces of the struts 702 willpush the outer balloon members 708 radially outwards against aprosthetic device (not shown) mounted thereon.

As discussed in other embodiments, the expansion device can be expandedin stages such as a first stage where only the struts 702 are expanded(to partially expand the prosthetic device) and a second stage where thestruts 702 and outer balloon members 708 are expanded (to fully expandthe prosthetic device). In addition, outer balloon members 708 arepreferably expandable independent of the mechanical components (e.g.,struts) of expansion device 700. Thus, for example, outer balloonmembers 708 can be expanded when the struts 702 of expansion device 700are in a collapsed state (FIG. 32) or a completely expanded state (FIG.33). Because outer balloon members are independently expandable, outerballoon members 708 can be expanded either before or after the expansionof struts 702. That is, as described in other embodiments herein, thesequence of expansion of the inner member (struts 702) and outer members(outer balloon member 708) can vary.

Expansion device 700 can be particularly advantageous in deliveringprosthetic heart valves because the mechanical struts 702 providesignificant expansion while at the same time allowing blood to passaround adjacent outer balloons and through the largely hollow internalportion of expansion device 700. Referring to FIGS. 36 and 37, forexample, it can be seen that the internal area (i.e., the area beneaththe outer balloon members 708) of expansion device 700 is mostly emptyspace which allows for significant blood perfusion through that portionof expansion device 700. In contrast, when the inner member is a balloonmember, the inner balloon member occupies a large portion of the innerarea of the expansion device and prevents blood perfusion through thatportion of the expansion device. Expansion device 700 is alsoparticularly advantageous because it combines the perfusion capabilitiesof a mechanical expansion member (e.g., struts 702) with the highpressure expansion strength associated with balloon expansions members.

FIGS. 38A-38C illustrate a method of deploying a prosthetic heart valvewithin a native aortic annulus. Referring to FIG. 38A, a delivery device720 is shown delivering a prosthetic heart valve 722 in a collapsedconfiguration. Delivery device 720 can deliver prosthetic valve 722 tothe treatment location using known procedures. For example, theprosthetic device can comprise a SAPIEN Transcatheter Heart Valve (THV)available from Edwards Lifesciences LLC and the prosthetic valve can bedelivered either through a transfemoral or transapical approach.

Prosthetic valve 722 can be mounted on an expansion device 724, whichcan be, for example, an expansion device of the type described hereinwith reference to FIG. 3. Prosthetic valve 722 is maneuvered within anative aortic valve annulus 726 for deployment using delivery device720. Referring to FIG. 38B, expansion device 724 is expanded byinflating the inner balloon member and the outer balloon members of theexpansion device 724. As illustrated by arrows B, blood can flow betweenthe proximal end 728 and distal end 730 of expansion device 724 throughthe perfusion pathways provided by the gaps 734 in the expansion device724 as described and shown herein (e.g., FIG. 4). After prostheticdevice 722 is deployed within the native aortic annulus 726, expansiondevice 724 can be collapsed (deflated) and removed from the aorticannulus (FIG. 38C).

As discussed above, the number and size of outer balloon members (e.g.,balloon members 52 in FIG. 3) can vary. When the expansion device isused to expand a prosthetic heart valve (e.g., as shown in FIG. 40), theexpansion device desirably expands to outer profile that engages withand expands the prosthetic heart valve to a shape that conforms to theanatomy of the native annulus. Thus, for example, when expanding aprosthetic heart valve within the annulus of a native aortic valve, itcan be desirable to expand the prosthetic heart valve into a generallyround cross-sectional shape.

Generally, an expansion device can achieve a rounder outer profile byincreasing the number of outer balloon members 52. However, a largernumber of outer balloon members 52 will generally result smaller gapsbeing formed between adjacent outer balloon members, which can reducethe total flow area across the expansion device. Accordingly, in someembodiments, an expansion device has outer balloon members of aparticular orientation and size so that the expansion device is capableof expanding a prosthetic heart valve to a generally roundcross-sectional shape while providing a large enough flow area acrossthe expansion device to permit a sufficient amount of blood perfusionbetween the proximal and distal ends of the expansion device.

In some embodiments, when the expansion device is in its expandedconfiguration, it can be desirable to provide an amount of flow areaacross the expansion device that is substantially equal to or greaterthan an effective orifice area (EOA) of the native valve that is beingreplaced by the prosthetic heart valve. In this manner, the same amountof blood perfusion across the native annulus can be achieved with theexpansion device in an expanded state within the native annulus as waspossible before the expansion device was positioned within the nativeannulus.

As noted above, calcification of a native aortic valve can significantlyreduce the size of the orifice. FIG. 39 is a schematic view of acalcified native aortic valve 800 during ventricular systole (e.g., inan open state). As seen in FIG. 39, because of calcification of nativeaortic valve 800, the three native leaflets 802, 804, 806 cannot fullyopen, which results in a reduced EOA 808 for native aortic valve 800.The EOA of a calcified aortic valve is generally estimated to be betweenabout 0.5 cm² and 0.7 cm². For example, the EOA for a native aorticvalve annulus having a diameter of about 23 mm the EOA is estimated tobe about 0.56 cm² and the EOA for a native aortic valve annulus having adiameter of about 26 mm is estimated to be about 0.65 cm².

FIG. 40 illustrates an expansion device 810 that is similar to expansiondevice 28 shown in FIG. 4. Expansion device 810 has an inner balloonmember 812 and seven outer balloon members 814. A prosthetic heart valve816 can be mounted on the outer surfaces of outer balloon members 814.As seen in FIG. 40, the seven outer balloon members 814 are ofsufficient number and size that, upon expansion of expansion device 810,outer balloon members 814 urge against prosthetic heart valve 816 andexpand it to a generally round cross-sectional shape. Gaps 818 areformed between adjacent outer balloon members 814 to provide a totalflow area that is equal to or exceeds the flow area of the EOA of thecalcified native aortic valve 800 shown in FIG. 39.

Accordingly, for a 23 mm prosthetic heart valve, a total flow areaprovided between the outer balloon members 814 is equal to or greaterthan about 0.56 cm². For a 26 mm prosthetic heart valve, a total flowarea provided between the outer balloon members 814 is equal to orgreater than about 0.65 cm². For native aortic valves of any size, thetotal area of gaps at any location along the length of expansion device810 is preferably greater than 0.7 cm² to ensure that the flow areaequals or exceeds the flow area of the EOA of the calcified nativeaortic valve. Thus, by providing a total area for blood perfusion thatis greater than 0.7 cm², a patient's blood flow condition will not bemade worse during delivery of a prosthetic heart valve mounted onexpansion device 810.

Table 1 below illustrates estimated total flow areas achieved byexpansion devices that have seven outer balloon members. It should beunderstood that an outer diameter of an expansion device generallycorresponds to the size of the prosthetic heart valve being expanded bythe expansion device.

TABLE 1 Total flow area Outer between gaps EOA of Prosthetic heart Innerballoon balloon adjacent outer calcified valve size member membersballoon native (diameter) (diameter) (diameter) members aortic valve 23mm 11 mm 6 mm 1.2 cm² 0.56 cm² 26 mm 13 mm 6 mm 1.8 cm² 0.65 cm²

As shown in Table 1 above, the total flow area of 23 mm and 26 mmprosthetic heart valves can be about twice that of the EOA of acalcified aortic annulus (e.g., 1.2>2(0.56) and 1.8>2(0.65)). Thus, insome embodiments, a total flow area of an expansion device can begreater than about twice the flow area of an EOA of a calcified valve.

For a prosthetic heart valve that has a desired expanded size of about23 mm, the inner balloon member preferably has a diameter that isbetween about 10 and 12 mm (more preferably about 11 mm) and the outerballoon members preferably have a diameter that is between about 5 and 7mm (more preferably about 6 mm). For a prosthetic heart valve that has adesired expanded size of about 26 mm, the inner balloon memberpreferably has a diameter that is between about 12 and 14 mm (morepreferably about 13 mm) and the outer balloon members preferably have adiameter that is between about 5 and 7 mm (more preferably about 6 mm).

Other size expansion devices can be utilized while still providing thedesired flow areas described above. For example, prosthetic heart valvescan be provided with diameters smaller than the 23 mm and 26 mmprosthetic heart valves shown in Table 1, such as 20 mm, and withdiameters larger than the 23 mm and 26 mm prosthetic heart valves shownin Table 1, such as 29 mm. For each size expansion device, the innerballoon member and outer balloon members are preferably sized to providea desired amount perfusion across the expansion device. For example, insome embodiments, each expansion device can be sized to provide anamount of flow area that is greater than about 0.7 cm² and/or an amountgreater than or equal to the EOA of the calcified valve.

In addition, in some embodiments, expansion device 810, like the otherexpansion devices described herein, can be used for valvuloplastyprocedures. In such procedures, the expansion devices can be configuredto provide an outer diameter that can be used to achieve the desiredamount of perfusion across the expansion device during a valvuloplastyprocedure. The outer diameter of the expansion devices can be generallythe same as the size of the prosthetic heart valves described above.Alternatively, in some embodiments, it may be desirable to provideexpansion devices that expand to an outer diameter that is smaller thanthose used for prosthetic heart valve expansion. For example, expansiondevices that expand to an outer diameter of about 16 mm or 17 mm can beprovided. Of course, if desired, such smaller size expansion devicescould also be used to expand similarly sized prosthetic heart valves.

FIG. 41 illustrates another embodiment of an expansion device 830configured to expand a prosthetic heart valve 832 within a nativeannulus. As in other embodiments described herein, an inner balloonmember 834 is surrounded by a plurality of outer balloon members 836.One or more of outer balloon members 836 can comprise enlarged portionsat one or both ends of the mounted prosthetic heart valve 832. Forclarity, expansion device 830 is illustrated in FIG. 41 with only twoouter balloon members 836; however, it should be understood that thenumber of outer balloon members can be the same as disclosed in otherembodiments, such as the seven balloon embodiment shown in FIG. 4 or theeight balloon embodiment shown in FIGS. 5A and 5B.

One or more outer balloon members 836 can have a proximal enlargedportion 838 and a distal enlarged portion 840. For example, each of theouter balloon members 836 can have enlarged portions 838, 840.Alternatively, fewer than all of outer balloon members 836 can haveenlarged portions 838, 840, since as few as one outer balloon members836 with enlarged portions 838, 840 can help to retain prosthetic heartvalve 832 on expansion device 830.

The distance between proximal and distal enlarged portions 838, 840 canbe large enough to receive the length of a crimped and/or expandedprosthetic heart valve 832 therebetween. In this manner, outer balloonmembers can have a peanut- or dumbbell-like shape that can help maintainprosthetic heart valve 832 on the generally flat, central portion ofouter balloon members 836 between the two enlarged portions 838, 840.When expansion device 830 is collapsed, the additional materialassociated with enlarged portions 838, 840 can help retain prostheticheart valve 832 in a crimped configuration (not shown) on expansiondevice 830. When expansion device is fully expanded (FIG. 41), enlargedportions 838, 840 are located adjacent the two ends of prosthetic heartvalve 832, thereby restricting movement of prosthetic heart valve 832relative to outer balloon members 836.

FIGS. 42-44 illustrate another embodiment of an expansion device 850.Expansion device 850 also comprises an inner balloon member 852 and aplurality of outer balloon members 854 as described in other embodimentsherein. However, the portion of outer balloon members 854 that comesinto contact with the valve has a length BL. Balloon length BL can alsobe referred to as the “working length” or “working portion” of theballoon since it is the portion of the balloon that contacts and urgesagainst a prosthetic heart valve causing the prosthetic heart valve toexpand.

In some embodiments, the working length BL of at least some of outerballoon members 854 is shorter than the length VL of the prostheticheart valve. By reducing the working length BL of the outer balloonmember, greater blood perfusion can be achieved across expansion device850. That is, the distance that blood must flow through the gaps in theouter balloon members is shortened, increasing the rate of blood flowacross expansion device 850.

FIG. 43A is a cross-sectional view taken along a working portion ofouter balloon members 854 (i.e., a portion that urges against andexpands the prosthetic heart valve). FIG. 43B is a cross-sectional viewtaken along a non-working portion of outer balloon members 854 (i.e., aportion that includes reduced-profile tail portions that do not urgeagainst and expand the prosthetic heart valve). Higher rates of bloodflow can be achieved across expansion device 850 in the area of thereduced-profile tail portions (i.e., the non-working portions of theouter balloon members) because there are larger gaps or openings betweenadjacent outer balloon members 854 in that area as shown in FIG. 43B.

FIG. 44 illustrates a prosthetic heart valve 856 expanded on theshorter, outer balloon members 854. As described above, blood can passmore easily through the shorter passageways provided by the gaps betweenadjacent outer balloon members 854, thereby permitting a greater amountof blood to perfuse across expansion device 850.

FIG. 45 illustrates another embodiment of an expansion device 860.Expansion device 860 also comprises an inner balloon member 862 and aplurality of outer balloon members 864 as described in other embodimentsherein. However, at least some of the outer balloon members 864 have aworking length BL that is shorter than the length of the valve VL. Asdescribed in the previous embodiment, by reducing the working length BLof an outer balloon member, greater blood perfusion can be achievedacross the expansion device.

In addition to having one or more outer balloon members 864 that have aworking length BL that is less than the length VL of a prosthetic heartvalve 866 mounted on expansion device 860, adjacent outer balloonmembers 864 can be staggered longitudinally so that they are not alignedwith one another along the length of inner balloon member 862. Thus, forexample, some outer balloon members 864 can be shifted towards aproximal end 867 of prosthetic heart valve 866 so that they are notpositioned directly under prosthetic heart valve 866 at its distal end869. Other outer balloon members 864 can be shifted toward the distalend 869 of prosthetic heart valve 866 so that they are not positioneddirectly under prosthetic heart valve 866 at its proximal end 867. Insome embodiments, outer balloon members 864 can be alternatelystaggered, as shown in FIG. 45, so that adjacent outer balloon members864 alternate from being shifted toward one side of proximal heart valve866 to the other.

By providing the staggered and/or alternating arrangements describedabove, blood perfusion across expansion device 860 can be increased. Inaddition, such a staggered arrangement can reduce the collapsed profileof expansion device 860 because less balloon material is required toproduce a balloon with a shorter working length.

FIG. 46 illustrates another embodiment of an expansion device 870.Expansion device 870 also comprises an inner balloon member 872 and aplurality of outer balloon members 874 as described in other embodimentsherein. FIG. 46 is a cross-sectional view of expansion device 870 takenalong a longitudinal centerline of the expansion device and showing onlytwo of the plurality of outer balloon members 874.

Each outer balloon member 874 has a tail portion 876 that extends from aproximal or distal end of each outer balloon member 874. The tailportions 876 are preferably attached to a portion of inner balloonmember 872 to achieve better control of outer balloon members 874 asthey collapse and expand. Thus, for example, tail portions 876 can befused or otherwise coupled to inner balloon member 872 at connectionpoints 878. By attaching tail portions 876 as close as possible to thebody of inner balloon member 872, movement of outer balloon members 874relative to inner balloon member 872 can be restricted, providing aconsistent expansion device.

In addition to fusing and/or coupling tail portions 876 of outer balloonmembers 874 to inner balloon member 872 as shown in FIG. 46, in someembodiments, adjacent outer balloon members 874 can be fused and/orfixedly coupled to one another to further control the movement of outerballoon members 874 relative to each other and inner balloon member 872.

The coupling of adjacent outer balloon members to one another and/or tothe inner balloon member can be achieved by coupling the balloonmaterial together. FIGS. 47A and 47B illustrate embodiments of coupledtail portions. FIG. 47A illustrates a cross-sectional view of a tailportion of an expansion device 880 that comprises an inner balloonmember 882 and a plurality of outer balloon members 884. Each outerballoon member is secured to an adjacent outer balloon member and to theinner balloon member.

In the embodiment shown in FIG. 47B, instead of simply coupling the tailportions together, the tail portions shown in FIG. 47A can be fusedtogether to form an integrated expansion device 890 with a plurality oflumens (i.e., one inner balloon lumen 892 and seven outer balloon lumen894). Fusing the tail portions together in this manner can provide forbetter control of expansion device by reducing movement between adjacentballoon members. In addition, by fusing each of the tail portionstogether, a diameter of that area of the expansion device can be reducedfrom a first larger diameter ϕ1 (FIG. 47A) to a second smaller diameterϕ2 (FIG. 47B) due to the use of shared wall sections between adjacent,fused balloon members. Accordingly, not only can the relative movementof balloon members be reduced and/or controlled by fusing adjacentballoon members together as described above, but the profile of theexpansion device can be further reduced.

FIGS. 48A and 48B illustrate a method for fusing tail portions ofexpansion member 890 by pre-shaping the tails of outer balloon members894 into a segment or shape that can facilitate fusing of adjacent tailportions. For example, to facilitate the fusing process, it can bedesirable to pre-shape the tails into wedge-shaped portions so that eachouter balloon members can be fused to the outer balloon members that areadjacent to it as shown in FIG. 48B. The tail portions can then be fusedtogether by placing the pre-shaped tail portions into a fixed, hot metaldie.

FIGS. 49, 50A, and 50B illustrate another embodiment of an expansiondevice 900. Expansion device 900 comprises an inner balloon member 902and a plurality of outer balloon members 904. Inner balloon member 902and outer balloon members 904 can be constructed by fusing portions of asingle balloon. Thus, for example, as shown in FIG. 49, a single ballooncan be pinched and/or fused along a plurality of lines 906 to providethe plurality of outer balloon members 904.

Because lines 906 do not extend the full length of the expansion device900, a cross section taken along line 50A-50A reveals only a singlelumen 909 at a proximal end 908 of expansion device 900. Similarly, if across section were taken near a distal end 910 of expansion device 900it would also show only a single lumen. As a result of the fusing ofportions of expansion device 900 along lines 906, lumen 909 splits intoa plurality of lumen between the proximal end 908 and distal end 910 ofexpansion device 900. The plurality of lumens include a central lumendefined by inner balloon member 902 and a plurality of lumens that aredefined by outer balloon members 904. FIG. 50B is a cross-sectional viewtaken along line 50B-50B in FIG. 49, showing how lumen 909 splits intoan inner lumen 912 and a plurality of outer lumen 914. Because all lumenare in fluid communication with one another, when an inflation fluid isdelivered into lumen 909, the inflation fluid simultaneously moves intoinner lumen 912 and outer lumens 914.

The expansion devices described herein can provide uniform radialexpansion of a valve annulus during a valvuloplasty procedure anduniform radial expansion of a prosthetic valve in a valve replacementprocedure. Also, it should be note that such expansion devices can beused in stand-alone valvuloplasty procedures, as well as invalvuloplasty procedures performed in preparation of a valve replacementprocedure. For example, the expansion device can be used to perform avalvuloplasty procedure and then used to expand a prosthetic device inthe same annulus. The expansion devices described herein can allow bloodto flow across and/or through the expansion device, which can allow thedevice to be expanded for a longer duration of time and can reduce theneed to pace the heart during a procedure where the expansion device isexpanded in an annulus.

The expansion devices described herein can radially expand a prostheticvalve to a shape that is generally circular in cross section byexpanding an inner, central expandable member and one or more outerexpandable members. Conventional multiple balloon expansion devices arenot capable of performing such uniform circular expansion while alsoproviding for sufficient blood perfusion across the expansion member.For example, a three balloon device with the three balloon memberspositioned side-by-side may provide passageways for blood perfusion, butit will expand to a shape that is tri-lobular in cross section—notcircular. The expansion devices described herein are capable ofexpanding to a shape that is substantially circular in cross section,while allowing sufficient blood to pass through the device. In addition,the sequential or staged expansion of the expansion devices describedherein can permit a substantially circular deployment of a prostheticvalve at each stage of deployment.

The methods and apparatuses provided herein also include securement andstabilizing means for securing prosthetic devices during deployment ofthe prosthetic valve in a native aortic valve annulus. Because of thesubstantial pressures present in the left ventricle, securement andstabilizing devices, such shown in FIGS. 18A-19C and FIGS. 27-31, can beuseful to maintain the prosthetic valve in position on the expansiondevice.

Various systems and methods are also provided for providing improvedstability of the catheter itself during a valvuloplasty or prostheticvalve implantation procedure. The following embodiments provide enhancedstability of a catheter to improve the accuracy with which a balloonmember and/or prosthetic device is delivered and/or positioned within anannulus of a native heart valve.

FIG. 51 illustrates a delivery catheter shaft 1000 with its distal end1002 positioned adjacent a native aortic valve 1004. Catheter shaft 1000is shown in a retrograde approach (i.e., against the direction of bloodflow). Such an approach can be achieved, for example, by inserting thecatheter shaft 1000 into the femoral artery of the patient and trackingthe delivery catheter, through the descending aorta 1006, over theaortic arch, and into the ascending aorta 1010. As used herein, unlessexplicitly stated otherwise, the term aortic arch refers to the portionsof the anatomy between the ascending aorta and the descending aorta, andalso generally include portions of both the ascending aorta and thedescending aorta. The terms inner wall or inner area refer to areas ofthe aortic arch that are generally at or near the inside portion of thecurvature of the aortic arch, while the terms outer wall or outer arearefer to areas of the aortic arch that are generally on the outerportion of the curvature of the aortic arch.

A stability member 1012 is coupled to a distal area 1014 and a proximalarea 1016 on catheter shaft 1000. Stability member 1012 can comprise apull wire that is fixedly coupled at distal area 1014 and movablycoupled at proximal area 1016. Thus, by applying tension to the pullwire (e.g., from a distal end of the delivery catheter), an operator cancause catheter shaft 1000 to flex or bend between distal and proximalareas 1014, 1016. The pull wire can comprise any suitable material,including for example, a round wire or flat ribbon.

As the pull wire is tightened, the pull wire is moved into contact withan inner area 1018 of the aortic arch (as shown by arrow 1020), whilecatheter shaft 1000 is pushed into contact with an outer area 1022 ofthe aortic arch (as shown by arrow 1024). Thus, the flexing of cathetershaft 1000 caused by the stability member 1012 can effectively wedge theflexing portion of catheter shaft 1000 within the aortic arch.

The amount of force (e.g., fixation) exerted on the aortic arch bycatheter shaft 1000 can vary depending on the location where the pullwire is coupled to the distal and proximal areas 1014, 1016.Accordingly, the fixation forces can be adjusted by moving thesecoupling areas either proximally or distally along the catheter shaft1000.

By flexing catheter shaft 1000 across the aortic arch in the mannershown in FIG. 51, a stable platform can be provided for performingvalvuloplasty and/or implanting a prosthetic device. For example, aballoon catheter (with or without a prosthetic device) can extend beyonddistal end 1004 until it is positioned within the native aortic valve1004. The greater the distance between distal area 1014 and distal end1002, the greater the stability provided to the balloon catheter (orother device extending from distal end 1002). Once positioned within thenative aortic valve, a balloon member of the balloon catheter can beexpanded to perform a valvuloplasty procedure and/or to expand aprosthetic device within the annulus of native aortic valve 1004.

The balloon member can comprise a conventional balloon member, with thestability shaft functioning to improve the positioning accuracy of theballoon member by reducing movement of the catheter shaft within theaortic arch. Alternatively, the balloon member can comprise a balloonmember that allows blood to perfuse across the balloon member whenexpanded, including, for example, the perfusion devices describedelsewhere herein. By combining a perfusion balloon member with astability member, the position of the delivery system can be remainsubstantially steady while the balloon member(s) are inflated or beinginflated within the native aortic valve. Thus, the stability shaft andperfusion balloons can help offset the environmental forces that candestabilize the delivery catheter, such as the flow of blood directedacross the aortic valve and the balloon member during ventricularsystole.

FIG. 52 illustrates another stability device 1030. In this embodiment,catheter shaft 1000 can be coaxially mounted with an outer shaft 1032.Stability device 1030 can comprise a tension member (or wire) coupled toa distal area 1034 of the catheter shaft 1000 and a distal area 1036 ofouter shaft 1032. Relative movement of catheter shaft 1000 and outershaft 1032 alters the tension caused by stability device 1030, causingcatheter shaft 1000 to flex and wedge itself within the aortic arch.Thus, in a manner similar to that shown in FIG. 51 and described above,as catheter shaft 1000 extends away from the distal area 1036 of outershaft 1032, the tension member is forced into inner area 1018 of theaortic arch (i.e., in the direction of arrow 1020) and catheter shaft1000 is pushed to an outer area 1022 of the aortic arch (i.e., in thedirection of arrow 1024). As tension member contacts the inner area 1018and catheter shaft 1000 contacts the outer area 1022, catheter 1000 andouter shaft 1032 are wedged or generally fixed within the aortic arch toprovide a stable platform for delivery of various catheters of devicefrom the distal end 1002 of catheter shaft 1000.

The tension member of the stability device 1030 can be a wire, polymer,nitinol metal band, cloth, stainless steel, or other suitable materialcapable of providing sufficient strength to wedge the catheter shaft1000 in the manner described above. Preferably, the tensioning member isalso selected so that can maintain atraumatic contact with the aorticarch during actuation of the stability device 1030.

FIG. 53 illustrates another catheter shaft 1040 that comprises astability portion 1042. Stability portion 1042 is formed to besubstantially stiffer than the rest of catheter shaft 1040. Stabilityportion 1042 can be flexed into the curvature shown in FIG. 53 (e.g.,tracking the curvature of the aortic arch) and its stiffness canmaintain it in that position. Stability portion 1042 can bepre-tensioned into the curvature shown in FIG. 53. Alternatively,stability portion can be articulated so that it can be forced into thecurvature shown in FIG. 53 by applying a tensioning force via a pullwire. However, in view of the stiffness of the stability portion 1042,the pull wire should be of sufficient size and strength to overcome thestiffness of the stability portion 1042. In addition, when positionedfor balloon deployment within the aortic annulus, the stability portion1042 preferably extends a sufficient distance into the descending aortato provide the desired stability. In some embodiments, the stabilityportion 1042 extends at least 10 cm into the descending aorta, morepreferably at least 12 cm and, even more preferably, at least 15 cm.

Although FIG. 53 is shown with catheter shaft 1040 spaced apart from thewalls of the aortic arch, it should be understood that portions ofcatheter shaft 1040 can be brought into contact with the walls of theaortic arch (and neighboring portions of the descending aorta). Forexample, catheter shaft 1040 can be flexed so that a proximal portion ofcatheter shaft 1040 contacts the inner area 1018 and a distal portion ofcatheter shaft 1040 contacts the outer area 1022, thereby furtherstabilizing catheter shaft 1040 by creating the wedging effect describedherein.

FIG. 53 illustrates a prosthetic device 1044 mounted on a ballooncatheter 1046 that extends from catheter shaft 1040. Although thisembodiment illustrates balloon expansion of a prosthetic device, itshould be understood that the stability device embodiments describedherein, like those described elsewhere, can be configured for balloondeployment of a prosthetic device, balloon deployment only (e.g., avalvuloplasty procedure), and/or for use with other prosthetic devices(e.g., self-expanding prosthetic devices).

FIG. 54 illustrates a catheter shaft 1050 that comprises a plurality offlexible locking sections 1052 that allow the catheter shaft 1050 toarticulate and bend to conform to the aortic arch. The locking sections1052 can flex and bend to allow the catheter shaft 1050 to negotiate theanatomy. One or more pull wires (not shown) can be coupled to the distalend 1054 of the catheter shaft. Once tension is applied to the pullwire, locking sections 1052 engage and lock together, stabilizingcatheter shaft 1050 by maintaining it in the desired curvature.

Locking sections 1052 can comprise any structures suitable for providingflexing (to allow delivery of catheter 1050 through the anatomy) untiltension is applied. In one embodiment, locking sections 1052 comprise aplurality of interlocking tubes with their proximal sides chamfered sothat they can be received in the distal portion of an adjacent tube. Astension is applied to the interlocking tubes, each tube is partlyreceived into a portion of an adjacent tube and the chamfered ends causethe tubes to lock together with the desired curvature. When the tensionis released, the tubes can separate again, thereby allowing the lockingsections 1052 to flex as the catheter shaft is withdrawn from thevasculature of the patient. The interlocking tubes can be formed ofmetal, polymers, or other suitable materials.

Again, although FIG. 53 is shown with catheter shaft 1050 spaced apartfrom the walls of the aortic arch, it should be understood that portionsof catheter shaft 1050 can be brought into contact with the walls of theaortic arch (and neighboring portions of the descending aorta) to wedgecatheter shaft 1050 between opposing walls of the aortic arch asdescribed herein.

FIGS. 55A-56B illustrate embodiments of catheter shafts that compriseone or more expansion devices (e.g., balloon members) positioned tostabilize the catheter shafts in and/or about the aortic arch. FIG. 55illustrates a stabilizing device 1060 that comprises a plurality ofballoon members 1062 that at least partially surround a catheter shaft1064. One or more lumens can extend the length of catheter shaft 1064 todeliver fluid to balloon members 1062.

Balloon members 1062 can expand to contact the inner walls of the aorticarch and/or the descending aorta 1006. Thus, as shown in FIG. 55A, theballoon members can expand to contact the inner and outer areas 1018,1022 of the aortic arch, thereby bracing or wedging the catheter shaft1064 within the aortic arch. Balloon members 1062 can be formed in anyway that allows for their expansion as shown in FIG. 55A. In oneembodiment, balloon members 1062 can be positioned within cut-outs orslots provided in an outer surface of catheter shaft 1064. By providingballoon members in such recesses, the profile of the balloon membersrelative to an outer diameter of catheter shaft 1064 can be reduced.

FIG. 55B illustrates a cross-sectional view of stabilizing device 1060.As shown in FIG. 55B, balloon members 1062 can be formed with generallythe same size. Alternatively, the size (e.g., diameter) of balloonmembers 1062 can vary. Thus, for example, a balloon member positionedadjacent inner area 1018 of aortic arch may be larger than a balloonmember positioned adjacent outer area 1022 of aortic arch. By varyingthe size of balloon member, the required amount of bending or flexing ofcatheter shaft 1064 can be adjusted.

As shown in FIG. 55B, one or more gaps 1066 can be provided betweenadjacent balloon members 1062. Such gaps 1066 can improve bloodperfusion across stabilizing device 1060. In other embodiments, balloonmembers 1062 can be shaped to provide even greater amounts of bloodperfusion between adjacent balloon members 1062.

In addition to balloon members, expansion members can comprisemechanical expansion devices. For example, similar to the open frameconfigurations shown in FIGS. 32-37, mechanical linkages or struts canalternatively, or additionally, be used to fix the catheter shaftrelative to the aortic arch. Because of their generally open frameconstruction, such configurations can allow for greater blood perfusionacross the expansion member.

FIG. 56A illustrates another embodiment of a stabilizing device 1070.Stabilizing device 1070 comprises a single balloon member 1072 thatexpands to stabilize catheter shaft 1074. As balloon member 1072expands, balloon member 1072 contacts the inner area 1018 of the aorticarch and, at the same time, pushes catheter shaft 1074 towards the outerarea 1022 of the aortic arch, thereby wedging catheter shaft 1074 withinthe aortic arch. Gaps 1076 can be provided between the catheter shaft1074 and balloon member 1072 to allow for blood perfusion. As describedabove, the balloon member 1072 can be constructed in various manners andthe shape of balloon member 1072 can be varied to improve stabilityand/or to increase the areas of blood perfusion across balloon member1072.

FIG. 57 illustrates another catheter shaft that is configured to bestabilized within the aortic arch to improve positioning of a ballooncatheter or other similar delivery devices. Catheter shaft 1080 is aflexible catheter shaft formed with at least two articulating areas toform a generally “question-mark”-like shape. A first articulating area1082 is formed at a proximal position on catheter shaft 1080 and thesecond articulating area 1084 is formed at a distal position on cathetershaft 1080. First and second articulating areas 1082, 1084 areconfigured to allow bending of the catheter shaft 1080 in oppositedirections at those locations.

Articulating areas 1082, 1084 can be formed by providing selective lasercuts along the shaft. The laser cuts in articulating area 1082 aredifferent from those in articulating area 1084 to allow for bending(i.e., articulation) of the shaft in opposite directions. A pull wirecan extend from a distal end 1086 of catheter shaft 1080 to a proximalend (not shown). By pulling on the pull wire, a tension is applied tothe catheter shaft 1080, causing the shaft to bend at articulating areas1082, 1084. As shown in FIG. 57, first articulating area 1082 isconfigured so that the shaft bends towards the outer area 1022 of theaortic arch and second articulating area 1084 is configured so that theshaft bends towards the inner area 1018 of the aortic arch.

As tension is applied by the pull wire, a portion of catheter shaft 1080proximal to the first articulating area 1082 is moved toward an innerarea 1008 of the aortic arch or descending aorta (i.e., in the directionof arrow 1086). As the first articulating area 1082 bends away from theinner area 1008, another portion of catheter shaft 1080 moves toward theouter area 1022 of the aortic arch or descending aorta (i.e., in thedirection of arrow 1088).

Because the first and second articulating areas 1082, 1084 bend inopposite directions as shown in FIG. 57, when tension is applied tocatheter shaft 1080, it moves into contact with opposing walls of theaortic arch or descending aorta. The contact of the catheter shaft 1080with opposing walls of the aortic arch or descending aorta cause thecatheter shaft to be wedged in place, thereby providing stability to anydevice (e.g., a balloon catheter) deployed therefrom.

First and second articular regions are preferably formed of materialsthat not only articulate, but that also become stiff when articulating.Thus, for example, articulating areas 1082, 1084 can comprise selectivelaser cuts at one or more locations that allow compression of thecatheter shaft 1080 in these regions and also allow the shaft to belocked when the pull wire is tensioned.

FIG. 58 illustrates another catheter shaft 1100 that is configured toprovide additional stability of the catheter across the aortic arch.Catheter shaft 1100 comprises at least two flex points 1102 and 1104.These flex points (shown schematically in FIG. 58) are areas or portionsof catheter shaft 1100 that are adapted to allow for a greater amount offlexing or bending in the vicinity of flex points 1102, 1104. In oneembodiment, flex points 1102, 1104 can comprise cut-out portions of aninner portion of catheter shaft 1100 that allow catheter shaft 1100 toflex a greater amount at those areas. Such cut-out portions can beformed, for example, by laser cutting small slits, notches, etc., alongthe inner portion of catheter shaft 1100.

Catheter shaft 1100 can comprise a pull wire extending along cathetershaft 1100 and fixed in the vicinity of distal end 1106. By applyingtension to pull wire, catheter shaft 1100 will flex as shown in FIG. 58.By providing flex points 1102, 1104, catheter shaft 1100 will bend orflex a greater amount at those areas, causing catheter shaft 1100 tomove adjacent an outer wall of the aortic arch or descending aorta asshown by arrow 1108. The movement of catheter shaft 1100 towards theouter wall of the aortic arch or descending aorta, the portion ofcatheter shaft 1100 between flex points 1102, 1104 is directed towardsthe inner area 1018 of the aortic arch (i.e., in the direction of arrow1110). As seen in FIG. 58, the portion of catheter shaft 1100 betweenflex points 1102, 1104 may bend or flex; however, the provision of flexpoints 1102, 1104 allow for greater flexing at flex points 1102, 1104than at the portion of catheter shaft 1100 that is between flex points1102, 1104.

As shown in FIG. 58, flex point 1104 is preferably provided at the areaof catheter shaft 1100 that contacts the inner area 1008 of the aorticarch. Thus, catheter shaft 1100 can bend or flex a greater amount at oraround the point that it contacts the inner area 1008 of the aortic arch(i.e., in the direction of arrow 1112), allowing shaft 1100 to wedge andstabilize itself between opposing walls of the aortic arch.

FIG. 59 illustrates another embodiment of a catheter shaft 1040 thatcomprises a stability portion 1042 that is formed with a tube member1090 having a plurality of cuts (e.g., gaps or openings along the lengthof tube member 1090 that are either preformed or otherwise cut into thetube) to provide improved flexibility of tube member 1090. Tube member1090 can be embedded in, or otherwise coupled to, the distal end of thecatheter shaft 1040. Stability portion 1042 can be, for example, aNitinol tube that is laser cut to allow for a predetermined amount offlexing in the distal end of catheter shaft 1040. As catheter shaft 1040moves through the aortic arch of the patient, stability portion 1042 canbe flexed in the manner shown in FIG. 59 (e.g., tracking the curvatureof the aortic arch). The increased stiffness of catheter shaft 1040 canhelp maintain catheter shaft 1040 in a desired position within theaortic arch. In addition, the stability portion 1042 can be configuredto resist bending so that it provides a springback force (e.g., a forcegenerally opposite the direction of the bending) thereby wedging ofcatheter shaft 1040 within the aortic arch as described elsewhereherein.

In this embodiment, and in others, one or more pull wires can beprovided along the length of catheter shaft 1040. For example, a pullring can be provided at the distal end of catheter shaft 1040 and one ormore pull wires can be coupled to the pull ring. In some embodiments,two pull wires can be coupled to the pull ring at different locations(e.g., at opposite sides of the pull ring) and extend along the lengthof catheter shaft 1040. The application of force to the pull wires(e.g., via an external handle) can impart a desired amount of flexing tothe portion of catheter shaft 1040 within the aortic arch. Also, theflexing of catheter shaft 1040 can effectively wedge the flexing portionof catheter shaft 1040 within the aortic arch as described elsewhereherein.

FIG. 60 illustrates a tube member 1090 with a plurality of cuts thatextend along the length of the tube member. The spacing of cuts in tubemember 1090 can vary. The cuts can be separate and distinct from oneanother, providing, for example, a “slotted” tube member as shown inFIG. 60. Alternatively, the plurality of cuts can be continuous orotherwise interconnected along the length of tube member 1090.

In some embodiments, cuts can be spaced from the distal and proximalends of the tube member 1090. For example, at the distal end, a firstcut can be spaced a distance L_(D) from the distal end, and at theproximal end, a first cut can be spaced a distance L_(P) from theproximal end. As shown in FIG. 60, L_(D) can be less than L_(P). Inaddition, the spacing between adjacent cuts in the tube can be selectedto provide a desired curvature of catheter shaft 1040. In someembodiments, cuts nearer the distal end can be spaced closer together toaccommodate a greater degree of flexing at the distal end and to provideincreased stiffness further away from the distal end of tube member1090. For example, lengths L₁, L₂, L₃, and L₄ depict distances betweenadjacent cuts along the length of tube member 1090, and the distancesbetween adjacent cuts increases along length of tube member 1090 so thatlength L₁ is less than length L₂, L₂ is less than length L₃, and L₃ isless than length L₄. In addition, although FIG. 60 depicts the cuts ashaving the same general size and shape, it should be understood that thesize and shape of individual cuts can vary to provide the desired amountof flexibility and/or stiffness along the length of tube member 1090.

FIG. 61 illustrates another embodiment utilizing a tube member. In thisembodiment, tube member 1090 is embedded in (or otherwise coupled to)balloon catheter 1046. Tube member 1090 can be formed in the samegeneral manner as described above with respect to the tube member shownFIGS. 59 and 60. Balloon catheter 1046 (with tube member 1090 embeddedtherein) is moveable relative to catheter shaft 1040. For convenience,catheter shaft 1040 is illustrated in FIG. 61 with a portion removed tomore clearly show balloon catheter 1046. One or more pull members can beprovided on balloon catheter 1046 to facilitate flexing of ballooncatheter 1046 within the aortic arch. Tube member 1090 stabilizesballoon catheter by increasing the stiffness of balloon catheter 1046and/or by causing balloon catheter 1046 to flex within catheter shaft1040, thereby pushing catheter shaft 1040 towards the other wall of theaortic arch and wedging catheter shaft 1040 within the aortic arch asdescribed elsewhere herein.

FIG. 62 illustrates another embodiment of a catheter shaft 1040 thatcomprises a stability portion 1042. In this embodiment, stabilityportion comprises a coil member embedded in (or otherwise coupled) thedistal end of the catheter shaft 1040 to provide greater stiffness tocatheter shaft 1040. Stability portion 1042 can be, for example, aNitinol coil that is configured to allow a predetermined amount offlexing in the distal end of catheter shaft 1040. The stiffness of thecoil member can vary along its length by varying the distance betweenadjacent turns of the coil. Thus, catheter shaft 1040 can be stabilizedwithin the aortic arch by increasing the stiffness of catheter shaft1040 and/or by causing catheter shaft 1040 wedge itself within theaortic arch as described elsewhere herein.

As described elsewhere herein, a pull ring 1092 can be provided at thedistal end of catheter shaft 1040. Pull wires 1094, 1096 can be coupledto pull ring 1092 at different locations (e.g., at opposite sides of thepull ring) and can extend along the length of catheter shaft 1040. Theapplication of force (e.g., in the direction of arrows F₁ and F₂ asillustrated in FIG. 62) to the pull wires 1094, 1096 via an externalhandle 1098 can cause a desired amount of flexing of catheter shaft 1040within the aortic arch. Pull wires 1094, 1096 can be independentlyand/or collectively pulled to alter the amount of flexing of cathetershaft 1040.

FIGS. 63 and 64 illustrates another embodiment in which one or morestability members 2000 are delivered through one or more lumens 2002 incatheter shaft 1040. As shown in FIG. 64, lumen(s) 2002 can extend thelength of catheter shaft 1040 to allow for introduction of the stabilitymember 2000 into catheter shaft 1040 from outside of the patient's body.As stability members 2000 are introduced into catheter shaft 1040 andmove across the bend of the aortic arch, stability members exert a forcegenerally opposite their bending direction (e.g., a springback force).This springback force can increase the stability of catheter shaft 1040by pushing catheter shaft 1040 against the outer walls of the aorticarch. Thus, as shown in FIG. 63, the insertion of stability member 2000into lumen 2002 causes catheter shaft 1040 to stiffen and move towardsthe outer wall of the aortic arch, thereby wedging or generally fixingthe distal end of catheter shaft 1040 within the aortic arch to providea more stable platform for delivery of various catheters of device fromthe distal end of catheter shaft 1040.

FIG. 65 illustrates an embodiment with a plurality of lumens 2002configured to receive a plurality of stability members 2000. Stabilitymembers 2000 can comprise wires, such as Nitinol wires, that can beadvanced through respective lumens 2002 along catheter shaft 1040 untilthe wires reach the distal end of catheter shaft 1040, causing thedistal end of catheter shaft to stiffen within the aortic arch asdiscussed above. Although FIG. 65 illustrates stability members as beinggenerally round in cross section, it should be understood that stabilitymembers can comprise other shapes, including, for example, generallyflat members (e.g., strips) that extend through correspondingly-shapedlumens. In addition, although FIG. 65 illustrates six lumens, it shouldbe understood that more or less than six lumens can be provided.

FIG. 66 illustrates another embodiment, in which a single lumen 2002 isprovided for receiving a stability member 2000. For example, FIG. 66illustrates stability member 2000 configured as a generally flat strip,such as a Nitinol strip. Lumen 2002 extends along the length of cathetershaft 1040, as shown in FIG. 64, to allow for introduction of the singlestability member 2000 into catheter shaft 1040 from outside of thepatient's body. Although the single lumen embodiment illustrates thestability member 2000 as a generally flat strip, it should be understoodthat members of other shapes can be utilized, including, for example,the generally round cross-sectional members described in the multi-lumenembodiment.

FIGS. 65 and 66 also illustrate another lumen for receiving one or morepull wires. It should be understood that additional lumen can beprovided in catheter shaft 1040, if additional pull wires are desired.

In operation, stability member(s) 2000 can be introduced into lumen(s)2002 of catheter shaft 1040 after the distal end of catheter shaft 1040is positioned within the aortic arch. After advancing stabilitymember(s) 2000 through the lumen(s) 2002, the springback force caused bythe bending of stability members 2000 causes catheter shaft 1040 tocontact one or more portions of the outer wall of the aortic arch,thereby wedging or otherwise generally fixing catheter shaft 1040 withinthe aortic arch to provide a more stable platform for delivery ofvarious catheters of device from the distal end of catheter shaft 1040,such as a prosthetic device 1044 on a balloon catheter 1046.

Although the detailed description generally describes the deployment ofa prosthetic valve within the aortic annulus, it should be understoodthat the expansion devices described herein can be used to expand otherprosthetic valves or stents in other areas of the body, including, forexample, the delivery of a bare stent in the coronary artery. Inaddition, the expansion devices described herein can also be used inother medical procedures where an annulus or passageway of thecardiovascular system is to be enlarged, either with or without thedeployment of a stent or other prosthetic member. For example, theexpansion devices described herein can be used in angioplastyprocedures, including for example, coronary artery dilation procedures.Similarly, the methods and systems disclosed herein for providingimproved stability to a catheter in the vicinity of a heart valve can begenerally applicable in other areas of the body. For example, thestability systems and methods illustrated in FIGS. 51-66 can be usefulto stabilize a catheter in connection with other medical procedures thatinvolve a bending or curving region similar to that of the aortic arch.

In addition, one of ordinary skill in the art would understand thatspecific features of the various embodiments can be combined in othermanners, unless those features are directly contradictory to each other.For example, a stiffer distal end portion (as shown, for example, inFIG. 53) can be combined with articulating portions or bend areas (asshown, for example, in FIGS. 57 and 58) to increase the stability of thedistal end portion of a catheter shaft by providing a stiffer distal endportion that can be more easily wedged or otherwise fixed in placerelative to a patient's aortic arch.

In view of the many possible embodiments to which the principles of thedisclosed invention may be applied, it should be recognized that theillustrated embodiments are only preferred examples of the invention andshould not be taken as limiting the scope of the invention. Rather, thescope of the invention is defined by the following claims. We thereforeclaim as our invention all that comes within the scope and spirit ofthese claims.

1. A method of implanting a prosthetic heart valve, the methodcomprising: advancing a distal end portion of a catheter shaft through apatient's vasculature, wherein the distal end portion of the cathetershaft comprises an expansion device, and wherein a prosthetic heartvalve is mounted on the expansion device, the expansion device and theprosthetic heart valve being in a compressed configuration; positioningthe distal end portion of the catheter shaft and the prosthetic heartvalve at or adjacent an implantation location; and expanding theprosthetic heart valve and the expansion device from the compressedconfiguration to an expanded configuration, wherein the expansion devicecomprises an inner expandable member and a plurality of outer expandablemembers, wherein the outer expandable members are distributedcircumferentially around the inner expandable member and arecircumferentially spaced apart relative to each such that there are gapsbetween adjacent outer expandable members providing perfusionpassageways between the expansion device and the prosthetic heart valvewhen the expansion device is in the expanded configuration.
 2. Themethod of claim 1, wherein each of the outer expandable memberscomprises a main portion, a proximal portion, and a distal portion, andwherein the proximal portion is circumferentially narrower than the mainportion.
 3. The method of claim 1, wherein each of the outer expandablemembers comprises a main portion, a proximal portion, and a distalportion, and wherein the distal portion is circumferentially narrowerthan the main portion.
 4. The method of claim 1, wherein each of theouter expandable members comprises a main portion, a proximal portion,and a distal portion, and wherein the proximal portion and the distalportion are circumferentially narrower than the main portion.
 5. Themethod of claim 1, wherein the outer expandable members comprise mainportions, proximal portions, and distal portions, and wherein theproximal portions are fixedly coupled to the inner expandable member. 6.The method of claim 1, wherein the outer expandable members comprisemain portions, proximal portions, and distal portions, and wherein thedistal portions are fixedly coupled to the inner expandable member. 7.The method of claim 1, wherein the outer expandable members comprisemain portions, proximal portions, and distal portions, and wherein theproximal portions and the distal portions are fixedly coupled to theinner expandable member.
 8. The method of claim 1, wherein the outerexpandable members comprise main portions, proximal portions, and distalportions, wherein the main portion can freely move relative to the innerexpandable member.
 9. The method of claim 1, wherein the expansiondevice is an inflatable balloon.
 10. The method of claim 1, wherein theexpansion device comprises at least five outer expandable members. 11.The method of claim 1, wherein the expansion device comprises at leastseven outer expandable members.
 12. A method of implanting a prostheticheart valve, the method comprising: advancing a distal end portion of acatheter shaft through a patient's vasculature, wherein the distal endportion of the catheter shaft comprises an expansion device, and whereina prosthetic heart valve is mounted on the expansion device, theexpansion device and the prosthetic heart valve being in a compressedconfiguration; positioning the distal end portion of the catheter shaftand the prosthetic heart valve at or adjacent an implantation location;and expanding the prosthetic heart valve and the expansion device fromthe compressed configuration to an expanded configuration, wherein theexpansion device comprises a main body and a plurality of projectionsextending radially from the main body, wherein the projections arespaced apart relative to each such that there are grooves extendingbetween adjacent projections providing perfusion passageways between theexpansion device and the prosthetic heart valve when the expansiondevice is in the expanded configuration.
 13. The method of claim 12,wherein the grooves of the expansion device comprise one or morelongitudinally-extending grooves.
 14. The method of claim 12, whereinthe grooves of the expansion device comprise one or morecircumferentially-extending grooves.
 15. The method of claim 12, whereinthe grooves of the expansion device comprise one or morelongitudinally-extending grooves and one or morecircumferentially-extending grooves, and wherein thelongitudinally-extending grooves intersect thecircumferentially-extending grooves.
 16. A method of implanting aprosthetic heart valve, the method comprising: advancing a distal endportion of a catheter shaft through a patient's vasculature, wherein thedistal end portion of the catheter shaft comprises an expansion device,and wherein a prosthetic heart valve is mounted on the expansion device,the expansion device and the prosthetic heart valve being in acompressed configuration; positioning the distal end portion of thecatheter shaft and the prosthetic heart valve at or adjacent animplantation location; and expanding the prosthetic heart valve and theexpansion device from the compressed configuration to an expandedconfiguration, wherein the expansion device comprises an innerexpandable member and an outer expandable member, wherein the outerexpandable member extends radially outwardly from the inner expandablemember and extends helically from a proximal portion end of the innerexpandable member to a distal end portion of the inner expandablemember, thereby forming a helical passageway between the expansiondevice and the prosthetic heart valve when the expansion device is inthe expanded configuration.
 17. The method of claim 16, wherein theouter expandable member comprises a main portion, a proximal portion,and a distal portion, and wherein the proximal portion and the distalportion are narrower than the main portion.
 18. The method of claim 16,wherein the outer expandable member comprises a main portion, a proximalportion, and a distal portion, and wherein the proximal portion and thedistal portion are fixedly coupled to the inner expandable member. 19.The method of claim 18, wherein the main portion is fixedly coupled tothe inner expandable member.
 20. The method of claim 18, wherein themain portion is freely movable relative to the inner expandable member.